May 29, 2024 • 46 mins
In the late 19th century, a French experiment demonstrated the power of stereo sound. A century later, experiments in binaural audio would help create rich soundscapes that could immerse the listener in audio environments. We learn about the evolution and tech of 3D audio.
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Speaker 1 (00:01):
iHeart three D Audio. This episode was brought to you
in iHeart three D Audio. To experience more podcasts like this,
search for iHeart three D Audio in the iHeartRadio app.
(00:24):
This special three D episode is sponsored by Audible, The Conjuring,
The Devil Made Me Do It, Rated R, and World
of Warcraft. For maximum effect, headphones are recommended. Welcome to
Tech Stuff, a production from iHeartRadio. Hey there, and Welcome
(00:48):
to tech Stuff. I'm your host, Jonathan Strickland. I'm an
executive producer with iHeart Podcasts and How the tech are you?
Speaker 2 (00:55):
So?
Speaker 1 (00:55):
I am currently on a short little out of town vacation.
I'll be back on Friday, but I wanted to have
an episode for y'all while I was gone. This one
originally aired on May tenth, twenty twenty one. It is
called how three D Audio Works. So at the time,
we at the company were kind of playing around with
(01:16):
three D audio sound and three D audio technology and
just kind of experimenting with it, and it was a
lot of fun to do that. I only got to
play with it a little bit. I didn't trust it
in my hands, but it did inspire me to do
an episode to really talk about three D audio and
binaral audio and that sort of thing. So I hope
you enjoy and I'll talk to you again when the
(01:39):
episode is concluded. Let me tell you a story about
my childhood. My family are all really big Disney theme
park fans, and growing up in Georgia meant we were
just a short eight to ten hour drive from Walt
Disney World in Florida. Both of my parents were teachers,
(02:03):
and they would save up money so that every two
or three years or so we'd make the trip down.
Disney World was always where my sister and I wanted
to go, even when my parents gently tried to suggest
other places like Washington, DC or New York City. Nope,
we wanted Disney World also quick aside, these days, we
(02:27):
still will take family trips to Disney World, my parents included,
and now with my nieces we get to experience seeing
Disney through fresh eyes, which is pretty great. But anyway,
back to my story. Back in nineteen eighty nine, the
Disney Hollywood Studios park opened for the first time. Back
then it was Disney MGM Studios, and the studios were
(02:49):
a working studio with films and TV shows shot on
the premises. A lot of attractions related to film and
TV production. There was the Great Movie Ride, which closed
in twenty seventeen. There was a Behind the Scenes Tour
which closed in twenty fourteen, and there were various experiences
that taught audiences about stuff like special effects, all of
(03:12):
which have closed. Almost leads you to the conclusion that
the Hollywood Studios aren't so much the Hollywood Studios anymore,
but I'm off track again. One of those experiences was
all about sound effects, and it was called the Monster
Sound Show. I remember that the attraction featured a clip
of a film starring Martin Short and Chevy Chase, and
(03:35):
it had a lot of sound effects that played in
that movie. Then the attraction host would bring up some
audience members to try and create sound effects live on
stage using various props while a silent version of the
film played, and then they would play the film back
again with the new audience supplied folly sound effects in
(03:57):
place to great comedic effect that presentation. However, you could
wander through the rest of the attraction and tucked off
to the side were a couple of rooms large enough
to hold a few people at a time, and they
were called Sound stations. Inside those rooms were benches attached
to the walls, and there were hooks holding headphones every
(04:18):
couple of feet you would go in, you would sit down,
you would put on the headphones, making sure that the
headphone with the yellow pad went over your right ear.
And then something extraordinary happened. As the lights went down,
you were presented with a scenario. You were playing the
part of a new executive at the Walt Disney Studios
(04:42):
named R. J.
Speaker 3 (04:43):
McBean.
Speaker 1 (04:45):
You're told you're sitting behind your executive desk waiting for
your assistant Hampton to come in and start off your day,
and the sound orbited you. You'd hear the narrator set
up the scenario and her voice drift from one ear
to the other as if she were actually walking around
(05:07):
you while you sat at this fictional desk. And then
the scenario would really begin and things got really wild.
A little tinker bell jingling would represent the true beginning,
and you would hear Hampton come in. He would walk
through on a door to your right, and then you'd
(05:29):
hear him pontificate as he walks through your office. He
would pour a fuzzy drink into a glass of ice
and he introduced you to your secretary surely, Oh and
also said you would get a haircut from a stylist
named Ken, because of course the big Cheese is on
(05:51):
his way to meet you. And the haircut sounds in
particular were really compelling. You could almost feel the since
of someone cutting your hair. And I say this as
a bald man who hasn't had hair in more than
twenty years. Meanwhile, as the hair goes flying, a director
called Flavio shows up and pitches a new film to you,
(06:14):
complete with using a hairdryer to simulate desert winds. There
are a lot of other cute sound effects that follow,
like a paper being placed over your head to represent
a turbin and you can actually find recordings of this
piece online, though I will warn you the effects aren't
(06:37):
quite up to the quality of the original attraction, which
also incorporated stuff like actual blowers to blow warm air
on you. Oh and that big cheese who comes in
at the end, well that's Mickey Mouse. Of course. He
comes into place a pair of mouse ears on top
of your head. The whole thing lasted about five minutes
(06:59):
and I loved it. And at the end you were
instructed to remove your headphones, hang them back on the wall,
and exit the room, whereupon you'd head outside to the
blazing Florida sun and the wild audio of the real outdoors.
That was how I first experienced three D audio. At
(07:20):
that time, it was based off a technology that had
a brand name of Holophonics. These days, we'd more likely
call it binarl audio or maybe just three D audio.
And there are a lot of different ways to create
the experience, some of which requires special equipment, others that
require special software. You can find examples of three D
(07:43):
audio in music recordings, amusement park attractions, and stuff like
ASMR videos. It can be a really compelling experience, and
I remember getting goosebumps the first time I encountered it,
and depending on who's doing the recording and the effect
that they're creating, I can still get goosebumps from it today.
(08:04):
Longtime listeners might remember that. A few years back, I
interviewed an ASMR artist named Heather Feather, who was one
of a handful of creators who are really making ASMR
a phenomenon. Now we have thousands of creators. If you
do a search on YouTube for ASMR, you will see
countless videos in the category, but the technology and psychology
(08:28):
behind this experience goes back quite a ways. So I
want to explore the evolution and technology behind making three
D audio. Now, in the beginning, there was mono, that
is monaural or monophonic sound. This sound can come from
a single loud speaker, or it could be channeled to
(08:51):
multiple loudspeakers, but the signal going to each loudspeaker is
exactly the same as every other loudspeaker. It's effective a
single channel of sound. It's how we do podcasts typically,
where you usually will hear the same level of volume
in each ear. For shows with multiple hosts, it means
(09:12):
that you hear all the hosts in both ears equally.
Most listeners tend to prefer that, but very early on
people started to experiment with ways to provide more than
one channel of sound simultaneously to a listener to create
a different kind of experience. Way back in eighteen eighty one,
when the loud speaker itself was just a few years old,
(09:36):
Alexander Graham Bell had patent it in eighteen seventy six
as part of his telephone invention. Well that's when a
man named Clement Adder came up with a clever idea.
One of the downsides of live theater is that it
is a scarce resource. Only so many people can fit
into a theater for a performance, and once that performance
(09:58):
is over, it's all done. So there is an element
of exclusivity when it comes to live theater, something that
remains true because I mean, it's just the limitations of
the art. But Adder thought of a way that would
help people listen in to say, a performance of an opera,
without having to actually go to the opera house. His
(10:19):
demonstration involved installing telephone receivers in a few rooms at
the Palais de Lindistri. The microphones he installed near the
footlights at the Grand Opera in Paris, so they were
across town. People could come into these rooms at the
Palais in small groups and they would hold two receivers,
(10:39):
one to each ear. Each receiver connected to a different microphone,
which meant the sound they were hearing was actually coming
from two different locations. In an article in Scientific American,
a Monsieur Hospitalier is quoted as saying, quote, everyone who
has been fortunate enough to hear the telephones at the
(11:00):
Palais de Lindiestri has remarked that in listening with both
ears at the two telephones, the sound takes a special
character of relief and localization which a single receiver cannot produce.
End quote. This was a very early and primitive version
of stereophonic sound. For those of us who have hearing
(11:22):
in both of our ears, we experience the world in stereo.
Sound travels at a certain speed. It's three hundred and
forty three meters per second if you have an air
temperature of around twenty degrees celsius or sixty eight degrees fahrenheit.
And yes, the temperature affects how quickly sound will move
through the air. And our ears are located upon opposite
(11:45):
sides of our noggins. That means that sound hits our
two ear drums at slightly different times, depending upon where
it's coming from, and we will perceive sound coming from
one side of us as being louder in that ear
than in our opposite ear, and so on. So mono
sound shoves all of those sound waves through one channel.
(12:07):
Everything is coming out equally through each loud speaker. Stereo sound, however,
changes this up, varying the amplitude or volume of sound
in each channel and creating a different effect. While adders
demonstration indicated that there was something interesting with producing sound
using different channels directed at different loudspeakers, that was just
(12:30):
the tip of the iceberg. Alan Dower Blumline would advance
the art considerably in the nineteen thirties. Blumline was born
in nineteen oh three. He became an electronics engineer and
he worked for the famous Abbey Road Studios where he
pioneered advancements in stereophonic recording. According to an anecdote told
(12:51):
by Alan Blumline's son, Simon, Blumline was at the movies
with his wife watching a film and he remarked that
we're a blind person to go to the movie, they
might struggle to follow what was going on because the
sound was all coming from loud speakers in mono. There
was no way to detect through hearing where people were
(13:11):
within a scene. Everyone would sound like they were in
the same spot. You would only be able to hear
if someone was further or closer to a microphone, but
otherwise spatially you would have no idea what was going on.
And that got him into thinking about developing a system
that would allow sound engineers to record and reproduce sound
so that had a more localized effect. Action happening on
(13:33):
the left side of the screen would be represented by
sounds emanating from loudspeakers on the left side of the theater. Likewise,
action on the right side would be paired with an
appropriate amount of sound coming from the right. Each speaker
might produce some of the sound, but at different amplitudes,
so that while you might get a little bit of
the right hand sound from left hand speakers, the levels
(13:57):
would be lower, and the overall feeling would be that
you're in the middle of that sound, and it would
enhance the experience of seeing a movie and as well
as help out those who are visually impaired follow what
was going on. According to that anecdote, Blumline called it
binaral sound, which of course we'll come back to a
bit later in this episode. I just find it interesting
(14:19):
that the original term for stereo is one we now
associate with a more specific approach to audio recording and production.
He would receive more than seventy patents for his various
inventions related to stereo sound. He created technology to record, process,
and reproduce audio in stereo. In nineteen thirty four, he
(14:41):
oversaw a stereo recording of the London Philharmonic Orchestra at
the Abbey Road Studios. Blomline also pioneered the Blumline method,
which would use two microphones mounted at a ninety degree
angle with regard to one another, to pick up directional
sounds in a recording environment. So words, if you think
of a room as a square, one mic is picking
(15:03):
up sounds primarily along the X axis, and the other
is picking up sound along the y axis. Blumline also
figured out how to create a stereo groove in a
record album. Back in those days, these were made from shellac,
but they would later be made from vinyl. And when
I think about that, I'm astonished. I mean, the way
(15:24):
a record player works is that a stylus or needle
fits into the groove of a record. That groove causes
the stylus to vibrate, and those vibrations transmit to a transducer,
which turns the vibrations into an electrical signal thanks to
a little electro magnet magic, and that signal then goes
to an amplifier, which boosts the signal strength, which then
(15:48):
goes on to loud speakers and powers them so that
they can reproduce the original recorded sound that created the
groove in the first place. It's the edges of these
grooves that cause the vibration or the wiggle of the stilus.
So how does one record stereo sound to a physical
disc with a groove. Well, imagine a groove that slaloms
(16:10):
back and forth in a nice even path, So the
waves along either side of the groove are a physical
representation of the original sound waves that were recorded. Now,
usually in a mono record, you would just see that
these waves are evenly distributed on the left and right side.
It's like they're in sync with one another. It's just
(16:31):
a nice smooth curve. But what if you wanted to
record stereo, Well, you could have it where the left
side of the groove and the right side of the
groove are actually different. The wall on one side would
represent the audio recorded in one channel, and the wall
on the other side of the groove was for the
second channel. So, with the proper equipment, you could play
(16:55):
this record back and the stylus would vibrate in a
very specific way. It would be detected by two sensors
connected to the stylus, So essentially two transducers, and these
two channels of sound could again go to specific loudspeakers
a left and a right, and then you get stereo playback.
It's pretty incredible. Listening back to properly recorded and processed
(17:18):
audio would give the listener the sensation that they were
actually in an acoustic space. It would feel as though
you were standing at the spot where the microphone had
been mounted, and that the sound you encounter is just
as if you were present at the recording session. That
was the intent, anyway, but the actual process of getting
(17:38):
there is a lot more complicated than setting up just
a pair of microphones. When we come back, we'll learn
a bit more about stereo recording and editing, and we'll
also learn why the Beatles, who also made famous recordings
at Abbey Road Studios, concentrated on creating mono records for
a long time, even though stereo had been around for decades.
(18:01):
But first, let's take a quick break. Now. I've done
episodes about sound to film in the past, and also
sound on television, so I'm going to skip over all
of that, Otherwise this episode would be for five hours long. Instead,
(18:24):
I want to talk a bit more about stereo recordings
and why bands like the Beatles were slow to adopt them.
To listen to a stereo recording properly, you need a
stereo system. That is, you need a sound system that
has at least two loud speakers and a way to
send the different channels of sound to both the left
and the right speakers or independently to the left and
(18:46):
right speakers. Otherwise, the playback would be in mono even
if the recording were in stereo, and what you would
get is a weird case where some elements of the
recording would be really quiet, as those would be the
sounds recorded to a channel that wasn't getting picked up
by the mono playback system. Now, if you've ever listened
to a recording where some of the voices or instruments
(19:07):
sound unusually quiet, and that it doesn't sound like this
was done on purpose, it's likely because either someone mixed
the audio improperly, or it's a stereo recording that at
some point got converted over into mono and you're losing
some of the audio as a result. Stereo systems were
really expensive when they first came out. I'm talking about
(19:30):
like stereo systems that you would purchase for your home,
and a lot of people, particularly young people, had really
purchased record players that had a single speaker incorporated into
the player itself, so these were mono playback devices as
there was only one speaker for sound to go. The Beatles,
being a band whose music was disproportionately favored by the young,
(19:53):
had their audience in mind as they mixed their albums.
It said that for many the albums from the early
to mid period of the Beatles as a band, the
group would spend hours in the mixing studio to get
the mono mix just right, but when it came time
to do the stereo mixes, they left that to the
(20:14):
audio engineers at Abbey Road and were never around. So
why is that, Well, because to them, the mono recordings
were more important. That was what their fan base could enjoy.
For that reason, a lot of Beatles fans or purists
favor the mono recordings of early Beatles work. They eschew
the stereo recordings as failing to represent what it was
(20:36):
the Beatles were trying to achieve. And if you listen
to the mono versus stereo recordings of some of those
early songs like Paperback writer or eleanor Rigby, you really
can tell there is a major difference, and this leads
into one way to create a stereo or three D
audio sound. You can take a recording and you can
(20:58):
change how much of the signal gets sent to a
particular channel. That determines which loud speaker or set of
loud speakers will play back the audio, or more likely,
how much volume that particular sound will have in each
loud speaker. This is both a science and an art.
A lot of the work in this field was centered
(21:18):
around music, and music can contain a wide range of
frequencies and tones. Imagine an orchestra. You have instruments that
primarily create lower frequencies, like lower pitches. You've got tubas
and basses and cellos. Each of those instruments, while creating
notes that might be in the same general range, have
(21:40):
distinct sounds. A tuba and an upright bass do not
sound the same. In other words, then you've got instruments
that center on some of the higher frequencies, like flutes
and piccolos and violins. These also sound different from one another,
and so it became important to figure out how to
not just capture a recording and divide it into channels
(22:04):
to create spatial landscapes, but also how to balance out
the tones so that you don't lose anything in the process.
With the wrong mix, one instrument or group of instruments
might totally overpower another, and it's almost as if those
other instruments were never even present at the original recording,
and so processing recordings and getting the mix just right
(22:26):
became critical. One part of this is called panning, and
it relies on a pan control. In the old days,
you would use a mixing board with physical controls on
it to control the pan. The pan determines how much
signal from each input is sent to each channel. These days,
many audio producers work with digital audio workstations or DAWs,
(22:51):
and with a DAW you also control panning. You can
pan either mono or stereo tracks. Most DAWs will let
you convert one type of track into another, splitting a
mono into stereo or a combining stereo into mono. For
certain types of audio, like mini podcasts, the default is
(23:11):
to go to mono. It can be a little disconcerting
if you record and publish a podcast in stereo. Many
years ago, when I first started recording large nerdron collider
with my friend Ariel. I accidentally recorded and published several
episodes in stereo, which meant all of my audio was
in one channel, like the left channel, and all of
(23:33):
Ariel's audio was in the other channel, the right channel.
So it's like I was talking into your left ear
and Ariel was talking into your right ear, which was
very unsettling. I eventually figured out what I was doing,
and I began mixing our recordings into a mono track
to avoid that problem. And with some early stereo recordings
(23:54):
you can hear examples of problems like this. It's frequently disconcerting.
There are records of songs in which all the instrumentation
is on one side and all the vocals are on
the other side. Now, that might have been done purposefully,
but it was often a sort of heavy handed approach
to stereo. There are times an artist might desire that
(24:16):
specific effect, but other times the desire was to be
a bit more creative with stereo, and you might have
a track in which the vocalist is on the extreme
right of part of the recording than on the extreme left.
Later on, the Beatles A Day in the Life actually
falls into that category. Or you might want to create
a rich soundscape in which there is a sense of
location for all the sound maybe not something that is
(24:40):
explicitly communicated to the listener, but is an important representation
of the performance. So how about we play around with
some post processing panning to create a three dimensional experience.
My producer, Tari, who is a superstar here at iHeart,
is always to the success of this show. But in
(25:02):
a moment, she's going to take over the experience of
what this show sounds like to you, the audience. And
I'm going to do something I've always wanted to do
in three D audio. I'm going to give you a
little Shakespeare. This piece is the prologue to Henry the Fifth,
one of Shakespeare's company Designated the chorus implores the audience
(25:24):
to use their imaginations to augment the production of the
play itself. And so as you listen to this piece,
imagine you are seated on a stage with the chorus
walking around you, explaining your role in creating the theatrical experience. Now,
I admit I'm cheating a little bit here, because the
(25:45):
whole point of this passage is to say that theater
is incapable of creating an exact copy of the story
of Henry the Fifth and England's battles with France. But
you also have to remember I'm a former English literature major,
and I never get to do Shakespeare. So here we go,
headphones on, Oh, for a muse of fire that would
(26:10):
ascend the brightest heaven of invention, a kingdom, for a stage,
princes to act, and monarchs to behold the swelling scene.
Then should the warlike Harry, like himself, assume the port
of Mars, and at his heels leashed in like hounds,
should famine sword and fire, crouch for employment. But pardon, gentles,
(26:36):
all the flat, unraised spirits that have dared on this
unworthy scaffold to bring forth so great an object. Can
this cockpit hold the vasty fields of France? Or may
we cram within this wooden o the very casks that
did affright the air at agincour pardon, since a crooked
(27:03):
figure may attest in little place a million, let us
ciphers to this great accompt on your imaginary forces work.
Suppose within the girdle of these walls are now confined
two mighty monarchies, whose high upreared and abutting fronts, the
(27:26):
perilous narrow ocean parts asunder, peace out our imperfections with
your thoughts into a thousand parts, divide one man and
make imaginary puissance. Think when we talk of horses, that
you see them printing their proud hoofs in the receiving earth.
(27:47):
Fortis your thoughts that now must deck our kings, carry
them here and there, jumping over times, turning the accomplishment
of many years into an hour for the which supply
admit me chorus to this history. Who prologue like your
(28:09):
humble patients, prey gently to hear, kindly to judge our play.
So for that recording, I went into our studio at iHeart,
and I spoke into a normal studio microphone. All the
manipulation had been done in post production, which is an
effective way to achieve that three D audio sound, but
(28:31):
it does require a lot of work on the part
of the producer. But the three D audio I did
at the top of this episode was done in a
different way. I used a special microphone. When we come back,
i'll talk a bit about that technology, and we'll learn
about some companies that have produced specialized equipment for the
purposes of three D audio. But first, let's take another
(28:55):
quick break. While some engineers and artists experimented with binaural
recordings for a while, it wasn't until nineteen seventy eight
that the first pop record using binaural recordings came out.
(29:15):
It was Lou Reed's Street Hassle. Listening to that album
with headphones on is pretty cool. To achieve the effect,
studio engineers took a mannequin head and installed a microphone
at each ear and use that to record sessions. A
company called Delta Acoustics put the system together with Manfred
Schunck supervising. Reed made a couple of other albums in
(29:39):
binarural audio. One was the Live Take No Prisoners album
and the other was The Bells. Other bands would experiment
and recorded binarl as well. The Rolling Stones did it
for their album Flashpoint, which was a concert recording of
some of their big hits and rarities. Pearl Jam record
a studio album called Binaral, recorded fittingly in Binarl. The
(30:04):
tech used to record these albums changed slightly, but it
was still based on the same underlying principles. I think
it's pretty widely understood that our ears receive sound in
the form of vibrations through a medium such as the air,
and then through interactions with the ear drum and the
cochlea and special nerves sending information to the brain. We
(30:24):
interpret those vibrations as sound in a very simple way
of looking at it. Sound comes into our ears. But
did you know our ears also generate sound, Because they
totally do. It's called autoacoustic emission ORAE. Now. To get
into OAEs, how they work and their role in stuff
(30:47):
like medicine is beyond the scope of this podcast, and
more importantly, way outside my general expertise. But it is
true that a very sensitive microphone inserted into the ear
canal of a person with hearing will pick up spontaneous
autoacoustic emissions or soaes. Now, most folks can't detect these sounds.
(31:12):
They tend to be at very low frequencies that dip
below human perception, and they are usually at very low amplitudes,
so they're pretty quiet. But in some cases people might
actually hear the sounds generated within their own inner ears
and experience it as tenetists. I'm one of those people,
(31:36):
yay me. Now, The reason I bring up that fact
that the inner ear can be not just a receptacle
for sound, but also a generator of sound. Is because
an inventor named Hugo Zucarelli used that as the basis
for a system he called holophonics. His idea was that
(31:57):
our hearing isn't a passive thing. That the inner ear
generates signals that interfere with the incoming audio signals, and
the resulting interaction between the sounds made by our ears
and the sounds coming into our ears plays a part
in sound localization. Now, long story short, Zucarelli's hypothesis doesn't
(32:20):
have a lot of support in the broader scientific community. However,
Zucarelli's equipment could record and reproduce sound in a really
interesting way. It's just the whole interference angle of what
was going on seemed inconsequential. Zucarelli used microphones to stand
in for human ears, spaced apart so that a sound
(32:42):
from any given direction would reach one microphone before the other,
and the amplitude of the signal would depend upon things
such as the distance between the microphone and the origin
of the sound, as well as the angle at which
the sound waves would reach the microphone. Zucarelli made a
bunch of different recordings to demonstrate this technology, something called
(33:02):
the Shaking Matchbox recordings, because that was one of the
sounds he actually recorded using this system. Whether his underlying
hypothesis was correct or not, the recordings were effective, and
Zucarelli's approach created a way to make really localized audio effects.
That's essentially what was going on with the Disney sound stations.
(33:24):
Some of the microphones used by recording studios even resembled
a human head, with microphones literally placed where the ears
should be, and that also plays a part in recording
a sound accurately so that the playback will seem as
though you are really there as you listen to it.
Beyond just the fact that our ears are on opposite
sides of our heads and the sound will reach each
(33:46):
ear at different times and amplitudes, other factors also shape
the nature of the sound. We perceive the shape of
our heads, the density of our noggins, our sinuses. All
of that affects our perception of sound. Collectively, we call
all of this head related transfer functions or HRTF. The
(34:08):
technology of holophonics systems and later binural microphones attempts to
replicate the experience of hearing hyperlocalized sounds through the application
of HRTF. But this process is incredibly complicated and it's mathy,
so I'm not going to go into deep detail, which
(34:30):
is good because I would likely mess up the explanation. Also,
it's important to acknowledge that every person is different, which
means there is no universal solution toward creating the perfect
binaural recording that will convince every listener that they are
hearing sounds coming from ultraspecific directions. You kind of have
to go more general to get a good response, but
(34:53):
the more precise you try to get, the more the
results will only work super well for a specific person
you know who whatever it was modeled for, and not
working quite as well for anyone else. For many years,
the microphones used to create binaural recordings in studio were
prohibitively expensive and far too complicated for the average consumer.
(35:17):
You would occasionally find binural recordings, such as the one
at Disney World, but these were pretty rare and very specialized,
and only big companies like Disney could afford to do them. However,
over time, companies began to develop microphones that fell more
into the range of the prosumer, with some consumer level
(35:37):
solutions thrown in there as well. Today there is a
range of microphones one can use to create three D audio.
The microphone I used earlier in this episode is a
three deo binural mic or a three D if you prefer.
You may have seen one of these if you watch
a lot of ASMR videos. They are very popular. The
(36:00):
microphone looks like a horizontal bar with two silicone ears
attached to either end of that bar. The ears are
spaced apart to mimic a typical human heads width. The
three D doesn't have the mass of a head, it's
just that bar in the ears. It doesn't have the
sinus cavities or anything like that. So it is not
(36:22):
a perfect simulacrum of a person's auditory system, but it
gets the job done. That style of microphone typically retails
are around four hundred dollars, so it's a little bit
on the pricey side, but it kind of falls between
consumer and prosumer. However, you can achieve similar results using
(36:42):
totally different microphone setups. They typically require XLR microphones that
connect to a recording device that can accept multiple inputs
recording each microphone to its own audio channel. It's possible
to use two normal microphones and space them apart from
each other and create a binaural experience, though it might
(37:03):
take some experimentation to get the spacing and gain levels
just right so that it all feels natural. Or of course,
you could just do it in post, but like I said,
that relies heavily on a ton of work on the
back end of things, and ASMR artists are not the
only ones using binaral audio. It's also useful for stuff
(37:25):
like virtual reality experiences and video games. Sound is a
powerful element that contributes to a sense of immersion, and
in some games it's critically important. For example, you might
play a first person shooter game like Player Unknowns Battlegrounds,
and you really need to use your ears to figure
out where other players are in relation to where you are.
(37:48):
Not doing so severely reduces your chances of making it
through the game. If you'd like to learn more, I
would recommend seeking out Old Tech Stuff episodes about surround sound,
which relates to this topic quite a bit, and also
our episodes about audio compression, as the process is designed
to compress audio. Tried to take the psychology of perception
(38:10):
into account. It's all fascinating stuff. As for three D audio,
I figure i'd leave you all with a little bit
of horror because three D audio works really well to
immerse a listener into a world, and it is particularly
well suited for tales of terror. Some of my coworkers
used it to great effect in a series called Thirteen
(38:33):
Days of Halloween, which we published last October, and so
here is a little excerpt from the show they produced.
Speaker 4 (38:43):
Ah, look at all the fun we're having in here.
I just knew you two would get along swimmingly. Oh no,
come with me, Surin.
Speaker 2 (38:55):
We'll catch up with you later. Dearhart is a truly
sweet young man. I've been attempting to persuade him to
see the good doctor about his cough, but he'll have
none of it. Maybe you could be of service in
that department. He really seemed to like you. Now, there
(39:16):
are hundreds of rooms here of the Hawthorne, but this
is perhaps the very finest, and it just so happens
to be your waters. Was it luck or.
Speaker 3 (39:29):
Fate that placed you here? We'll never know.
Speaker 5 (39:36):
I trust that you'll find everything to your liking. And
if you don't notify me and I will make sure
it is rectified. It's all part of my role here
as the caretaker. You know, your lack of verbal reciprocation
is really breaking down my sense of boundaries. I can
trust you, right of course I care.
Speaker 3 (40:02):
In these coming days, you may notice that Hawthorne manner
has no shortage of oddities. I've witnessed things myself that
strain the belief. But there is one strange legend that
has truly become something of an obsession. Supposedly, somewhere within
(40:24):
these halls there is a hidden doorway. If the tale
of what lurks on the other side is to be believed,
then gaining access would mean a sort of ascension beyond
human imagination, true immortality. I have come to understand that
one of our guests knows how to locate and open
(40:48):
this door. Perhaps what they cannot say to me, they
will happily divulge to you. I have a feeling your
quiet fortitude will lure them into a sense of intimacy.
Speaker 2 (41:04):
It certainly works on me.
Speaker 3 (41:08):
Please make yourself at home. After all, this is it.
There are so many others I cannot wait for you
to meet.
Speaker 1 (41:22):
Well. That wraps up this special episode of tech Stuff.
Several of the iHeart shows are including some binaral audio segments,
and we've got a lot planned into three D audio
space in the days up ahead. I really recommend you
check it out and explore some of the three D
audio recordings that are available online. You know that Disney
(41:45):
one I mentioned, There are actually versions of that up
on YouTube. People have the recordings up. I will say
that when I was listening back, it sounded like the
channels had been swapped. Everything that was supposed to be
in my right ear seemed to be coming through the
left ear. And I made sure that I was wearing
the headphones correctly. That's an important point, by the way.
(42:05):
If you're not wearing your headphones with the proper phone
over the proper ear, it's very disconcerting. I double checked
I was doing it correctly. Everything still seemed flipped and
the effect was not nearly as impressive as it was
when I went back to Disney. But I should also
add the Disney version incorporated some stuff that headphones just
(42:26):
can't do, stuff like a blower behind each person's back,
so that when you're getting a haircut in that sequence,
the hair dryer would actually blow air on you, so
that would add to your sense of immersion as it stands.
For me, if I'm listening to a very well recorded
three D audio setup, then if someone speaking quietly into
(42:51):
my ear, it's as if I can feel it, because
we have to remember sound when it gets down to it, Really,
that's just vibration. Those vibrations include fluctuations and air pressure.
So if you are listening to someone talk into your
ear through a speaker, you will feel it because those
are fluctuations in air pressure. It's not something you're imagining.
(43:14):
You are feeling it. It might be heightened because of
the way the audio is recorded, but it's actually happening
to you. I think three D audio is an incredible technology.
There's a lot more we could say about it, and
not just from the technological side, but the psychological side
and the biological side. So maybe I will do future
(43:36):
episodes that will focus on this more. I hope I
get a chance to play with the three D audio
microphone more. That was a lot of fun. I really
enjoyed doing that. I hope that I get to participate
in some of the three D audio recordings that we
have planned coming up, including some that are delving into
different areas of fiction. I would love to do that. Honestly,
(43:59):
I would love to do a full three D audio
version of a Shakespearean play. It is something I have
really wanted to do for a long time. I'm not
even talking about necessarily being in it, although it would
kill me not to be, but to be able to
experience a three D audio version of one of Shakespeare's plays,
(44:19):
to me, would be unbelievably amazing. So if you think
that's interesting, you should write to iHeart and let them know,
because I think it would be great. I wouldn't mind
working on something like that and let me know what
play you think we should do. Honestly, I'm thinking like
much ado about nothing. I think a comedy might be fun. Well,
(44:42):
I hope you enjoyed that episode from twenty twenty one
how three D audio works. I think three D audio
can really be fascinating and really immersive. Like I still
really love ASMR videos that do the ear to ear
stuff and use a lot of spatial audio. Well, it's
not as common now like that was like a big
(45:03):
thing many years ago when ASMR was first really starting
to take off. But these days I seem to see
a lot more things that are based off specific what
they call triggers, specific sounds, or specific effects, but less
the ear to ear stuff, which is the evolution of
the field. But it makes me miss the really cool
(45:24):
three D audio things that make you feel like you're
in an actual space with people really moving around you.
To me like, that's just an effect that I can't
get enough of. So that's kind of why I wanted
to go back and revisit this episode. I'll be back
on Friday with a new episode about tech news. We'll
find out what the heck happened on the week of
Memorial Day. I'm recording this the week before, so I
(45:47):
don't have any clue. As we've established many times, I
am not good at predicting the future, so I'll find
out when you all do. So I hope you are
having a great week, and I'll talk to you again
really soon. Tex Stuff is an iHeartRadio production. For more
(46:10):
podcasts from iHeartRadio, visit the iHeartRadio app Apple Podcasts for
wherever you listen to your favorite shows. This episode was
brought to you in iHeart three D Audio. To experience
more podcasts like this, search for iHeart three D audio
in the iHeartRadio app. Thank you to our sponsors, Audible,
(46:33):
The Conjuring, The Devil Made Me do It, Rated R,
and World of Warcraft.
iHeart three D Audio. This episode was brought to you
in iHeart three D Audio. To experience more podcasts like this,
search for iHeart three D Audio in the iHeartRadio app.
(00:24):
This special three D episode is sponsored by Audible, The Conjuring,
The Devil Made Me Do It, Rated R, and World
of Warcraft. For maximum effect, headphones are recommended. Welcome to
Tech Stuff, a production from iHeartRadio. Hey there, and Welcome
(00:48):
to tech Stuff. I'm your host, Jonathan Strickland. I'm an
executive producer with iHeart Podcasts and How the tech are you?
Speaker 2 (00:55):
So?
Speaker 1 (00:55):
I am currently on a short little out of town vacation.
I'll be back on Friday, but I wanted to have
an episode for y'all while I was gone. This one
originally aired on May tenth, twenty twenty one. It is
called how three D Audio Works. So at the time,
we at the company were kind of playing around with
(01:16):
three D audio sound and three D audio technology and
just kind of experimenting with it, and it was a
lot of fun to do that. I only got to
play with it a little bit. I didn't trust it
in my hands, but it did inspire me to do
an episode to really talk about three D audio and
binaral audio and that sort of thing. So I hope
you enjoy and I'll talk to you again when the
(01:39):
episode is concluded. Let me tell you a story about
my childhood. My family are all really big Disney theme
park fans, and growing up in Georgia meant we were
just a short eight to ten hour drive from Walt
Disney World in Florida. Both of my parents were teachers,
(02:03):
and they would save up money so that every two
or three years or so we'd make the trip down.
Disney World was always where my sister and I wanted
to go, even when my parents gently tried to suggest
other places like Washington, DC or New York City. Nope,
we wanted Disney World also quick aside, these days, we
(02:27):
still will take family trips to Disney World, my parents included,
and now with my nieces we get to experience seeing
Disney through fresh eyes, which is pretty great. But anyway,
back to my story. Back in nineteen eighty nine, the
Disney Hollywood Studios park opened for the first time. Back
then it was Disney MGM Studios, and the studios were
(02:49):
a working studio with films and TV shows shot on
the premises. A lot of attractions related to film and
TV production. There was the Great Movie Ride, which closed
in twenty seventeen. There was a Behind the Scenes Tour
which closed in twenty fourteen, and there were various experiences
that taught audiences about stuff like special effects, all of
(03:12):
which have closed. Almost leads you to the conclusion that
the Hollywood Studios aren't so much the Hollywood Studios anymore,
but I'm off track again. One of those experiences was
all about sound effects, and it was called the Monster
Sound Show. I remember that the attraction featured a clip
of a film starring Martin Short and Chevy Chase, and
(03:35):
it had a lot of sound effects that played in
that movie. Then the attraction host would bring up some
audience members to try and create sound effects live on
stage using various props while a silent version of the
film played, and then they would play the film back
again with the new audience supplied folly sound effects in
(03:57):
place to great comedic effect that presentation. However, you could
wander through the rest of the attraction and tucked off
to the side were a couple of rooms large enough
to hold a few people at a time, and they
were called Sound stations. Inside those rooms were benches attached
to the walls, and there were hooks holding headphones every
(04:18):
couple of feet you would go in, you would sit down,
you would put on the headphones, making sure that the
headphone with the yellow pad went over your right ear.
And then something extraordinary happened. As the lights went down,
you were presented with a scenario. You were playing the
part of a new executive at the Walt Disney Studios
(04:42):
named R. J.
Speaker 3 (04:43):
McBean.
Speaker 1 (04:45):
You're told you're sitting behind your executive desk waiting for
your assistant Hampton to come in and start off your day,
and the sound orbited you. You'd hear the narrator set
up the scenario and her voice drift from one ear
to the other as if she were actually walking around
(05:07):
you while you sat at this fictional desk. And then
the scenario would really begin and things got really wild.
A little tinker bell jingling would represent the true beginning,
and you would hear Hampton come in. He would walk
through on a door to your right, and then you'd
(05:29):
hear him pontificate as he walks through your office. He
would pour a fuzzy drink into a glass of ice
and he introduced you to your secretary surely, Oh and
also said you would get a haircut from a stylist
named Ken, because of course the big Cheese is on
(05:51):
his way to meet you. And the haircut sounds in
particular were really compelling. You could almost feel the since
of someone cutting your hair. And I say this as
a bald man who hasn't had hair in more than
twenty years. Meanwhile, as the hair goes flying, a director
called Flavio shows up and pitches a new film to you,
(06:14):
complete with using a hairdryer to simulate desert winds. There
are a lot of other cute sound effects that follow,
like a paper being placed over your head to represent
a turbin and you can actually find recordings of this
piece online, though I will warn you the effects aren't
(06:37):
quite up to the quality of the original attraction, which
also incorporated stuff like actual blowers to blow warm air
on you. Oh and that big cheese who comes in
at the end, well that's Mickey Mouse. Of course. He
comes into place a pair of mouse ears on top
of your head. The whole thing lasted about five minutes
(06:59):
and I loved it. And at the end you were
instructed to remove your headphones, hang them back on the wall,
and exit the room, whereupon you'd head outside to the
blazing Florida sun and the wild audio of the real outdoors.
That was how I first experienced three D audio. At
(07:20):
that time, it was based off a technology that had
a brand name of Holophonics. These days, we'd more likely
call it binarl audio or maybe just three D audio.
And there are a lot of different ways to create
the experience, some of which requires special equipment, others that
require special software. You can find examples of three D
(07:43):
audio in music recordings, amusement park attractions, and stuff like
ASMR videos. It can be a really compelling experience, and
I remember getting goosebumps the first time I encountered it,
and depending on who's doing the recording and the effect
that they're creating, I can still get goosebumps from it today.
(08:04):
Longtime listeners might remember that. A few years back, I
interviewed an ASMR artist named Heather Feather, who was one
of a handful of creators who are really making ASMR
a phenomenon. Now we have thousands of creators. If you
do a search on YouTube for ASMR, you will see
countless videos in the category, but the technology and psychology
(08:28):
behind this experience goes back quite a ways. So I
want to explore the evolution and technology behind making three
D audio. Now, in the beginning, there was mono, that
is monaural or monophonic sound. This sound can come from
a single loud speaker, or it could be channeled to
(08:51):
multiple loudspeakers, but the signal going to each loudspeaker is
exactly the same as every other loudspeaker. It's effective a
single channel of sound. It's how we do podcasts typically,
where you usually will hear the same level of volume
in each ear. For shows with multiple hosts, it means
(09:12):
that you hear all the hosts in both ears equally.
Most listeners tend to prefer that, but very early on
people started to experiment with ways to provide more than
one channel of sound simultaneously to a listener to create
a different kind of experience. Way back in eighteen eighty one,
when the loud speaker itself was just a few years old,
(09:36):
Alexander Graham Bell had patent it in eighteen seventy six
as part of his telephone invention. Well that's when a
man named Clement Adder came up with a clever idea.
One of the downsides of live theater is that it
is a scarce resource. Only so many people can fit
into a theater for a performance, and once that performance
(09:58):
is over, it's all done. So there is an element
of exclusivity when it comes to live theater, something that
remains true because I mean, it's just the limitations of
the art. But Adder thought of a way that would
help people listen in to say, a performance of an opera,
without having to actually go to the opera house. His
(10:19):
demonstration involved installing telephone receivers in a few rooms at
the Palais de Lindistri. The microphones he installed near the
footlights at the Grand Opera in Paris, so they were
across town. People could come into these rooms at the
Palais in small groups and they would hold two receivers,
(10:39):
one to each ear. Each receiver connected to a different microphone,
which meant the sound they were hearing was actually coming
from two different locations. In an article in Scientific American,
a Monsieur Hospitalier is quoted as saying, quote, everyone who
has been fortunate enough to hear the telephones at the
(11:00):
Palais de Lindiestri has remarked that in listening with both
ears at the two telephones, the sound takes a special
character of relief and localization which a single receiver cannot produce.
End quote. This was a very early and primitive version
of stereophonic sound. For those of us who have hearing
(11:22):
in both of our ears, we experience the world in stereo.
Sound travels at a certain speed. It's three hundred and
forty three meters per second if you have an air
temperature of around twenty degrees celsius or sixty eight degrees fahrenheit.
And yes, the temperature affects how quickly sound will move
through the air. And our ears are located upon opposite
(11:45):
sides of our noggins. That means that sound hits our
two ear drums at slightly different times, depending upon where
it's coming from, and we will perceive sound coming from
one side of us as being louder in that ear
than in our opposite ear, and so on. So mono
sound shoves all of those sound waves through one channel.
(12:07):
Everything is coming out equally through each loud speaker. Stereo sound, however,
changes this up, varying the amplitude or volume of sound
in each channel and creating a different effect. While adders
demonstration indicated that there was something interesting with producing sound
using different channels directed at different loudspeakers, that was just
(12:30):
the tip of the iceberg. Alan Dower Blumline would advance
the art considerably in the nineteen thirties. Blumline was born
in nineteen oh three. He became an electronics engineer and
he worked for the famous Abbey Road Studios where he
pioneered advancements in stereophonic recording. According to an anecdote told
(12:51):
by Alan Blumline's son, Simon, Blumline was at the movies
with his wife watching a film and he remarked that
we're a blind person to go to the movie, they
might struggle to follow what was going on because the
sound was all coming from loud speakers in mono. There
was no way to detect through hearing where people were
(13:11):
within a scene. Everyone would sound like they were in
the same spot. You would only be able to hear
if someone was further or closer to a microphone, but
otherwise spatially you would have no idea what was going on.
And that got him into thinking about developing a system
that would allow sound engineers to record and reproduce sound
so that had a more localized effect. Action happening on
(13:33):
the left side of the screen would be represented by
sounds emanating from loudspeakers on the left side of the theater. Likewise,
action on the right side would be paired with an
appropriate amount of sound coming from the right. Each speaker
might produce some of the sound, but at different amplitudes,
so that while you might get a little bit of
the right hand sound from left hand speakers, the levels
(13:57):
would be lower, and the overall feeling would be that
you're in the middle of that sound, and it would
enhance the experience of seeing a movie and as well
as help out those who are visually impaired follow what
was going on. According to that anecdote, Blumline called it
binaral sound, which of course we'll come back to a
bit later in this episode. I just find it interesting
(14:19):
that the original term for stereo is one we now
associate with a more specific approach to audio recording and production.
He would receive more than seventy patents for his various
inventions related to stereo sound. He created technology to record, process,
and reproduce audio in stereo. In nineteen thirty four, he
(14:41):
oversaw a stereo recording of the London Philharmonic Orchestra at
the Abbey Road Studios. Blomline also pioneered the Blumline method,
which would use two microphones mounted at a ninety degree
angle with regard to one another, to pick up directional
sounds in a recording environment. So words, if you think
of a room as a square, one mic is picking
(15:03):
up sounds primarily along the X axis, and the other
is picking up sound along the y axis. Blumline also
figured out how to create a stereo groove in a
record album. Back in those days, these were made from shellac,
but they would later be made from vinyl. And when
I think about that, I'm astonished. I mean, the way
(15:24):
a record player works is that a stylus or needle
fits into the groove of a record. That groove causes
the stylus to vibrate, and those vibrations transmit to a transducer,
which turns the vibrations into an electrical signal thanks to
a little electro magnet magic, and that signal then goes
to an amplifier, which boosts the signal strength, which then
(15:48):
goes on to loud speakers and powers them so that
they can reproduce the original recorded sound that created the
groove in the first place. It's the edges of these
grooves that cause the vibration or the wiggle of the stilus.
So how does one record stereo sound to a physical
disc with a groove. Well, imagine a groove that slaloms
(16:10):
back and forth in a nice even path, So the
waves along either side of the groove are a physical
representation of the original sound waves that were recorded. Now,
usually in a mono record, you would just see that
these waves are evenly distributed on the left and right side.
It's like they're in sync with one another. It's just
(16:31):
a nice smooth curve. But what if you wanted to
record stereo, Well, you could have it where the left
side of the groove and the right side of the
groove are actually different. The wall on one side would
represent the audio recorded in one channel, and the wall
on the other side of the groove was for the
second channel. So, with the proper equipment, you could play
(16:55):
this record back and the stylus would vibrate in a
very specific way. It would be detected by two sensors
connected to the stylus, So essentially two transducers, and these
two channels of sound could again go to specific loudspeakers
a left and a right, and then you get stereo playback.
It's pretty incredible. Listening back to properly recorded and processed
(17:18):
audio would give the listener the sensation that they were
actually in an acoustic space. It would feel as though
you were standing at the spot where the microphone had
been mounted, and that the sound you encounter is just
as if you were present at the recording session. That
was the intent, anyway, but the actual process of getting
(17:38):
there is a lot more complicated than setting up just
a pair of microphones. When we come back, we'll learn
a bit more about stereo recording and editing, and we'll
also learn why the Beatles, who also made famous recordings
at Abbey Road Studios, concentrated on creating mono records for
a long time, even though stereo had been around for decades.
(18:01):
But first, let's take a quick break. Now. I've done
episodes about sound to film in the past, and also
sound on television, so I'm going to skip over all
of that, Otherwise this episode would be for five hours long. Instead,
(18:24):
I want to talk a bit more about stereo recordings
and why bands like the Beatles were slow to adopt them.
To listen to a stereo recording properly, you need a
stereo system. That is, you need a sound system that
has at least two loud speakers and a way to
send the different channels of sound to both the left
and the right speakers or independently to the left and
(18:46):
right speakers. Otherwise, the playback would be in mono even
if the recording were in stereo, and what you would
get is a weird case where some elements of the
recording would be really quiet, as those would be the
sounds recorded to a channel that wasn't getting picked up
by the mono playback system. Now, if you've ever listened
to a recording where some of the voices or instruments
(19:07):
sound unusually quiet, and that it doesn't sound like this
was done on purpose, it's likely because either someone mixed
the audio improperly, or it's a stereo recording that at
some point got converted over into mono and you're losing
some of the audio as a result. Stereo systems were
really expensive when they first came out. I'm talking about
(19:30):
like stereo systems that you would purchase for your home,
and a lot of people, particularly young people, had really
purchased record players that had a single speaker incorporated into
the player itself, so these were mono playback devices as
there was only one speaker for sound to go. The Beatles,
being a band whose music was disproportionately favored by the young,
(19:53):
had their audience in mind as they mixed their albums.
It said that for many the albums from the early
to mid period of the Beatles as a band, the
group would spend hours in the mixing studio to get
the mono mix just right, but when it came time
to do the stereo mixes, they left that to the
(20:14):
audio engineers at Abbey Road and were never around. So
why is that, Well, because to them, the mono recordings
were more important. That was what their fan base could enjoy.
For that reason, a lot of Beatles fans or purists
favor the mono recordings of early Beatles work. They eschew
the stereo recordings as failing to represent what it was
(20:36):
the Beatles were trying to achieve. And if you listen
to the mono versus stereo recordings of some of those
early songs like Paperback writer or eleanor Rigby, you really
can tell there is a major difference, and this leads
into one way to create a stereo or three D
audio sound. You can take a recording and you can
(20:58):
change how much of the signal gets sent to a
particular channel. That determines which loud speaker or set of
loud speakers will play back the audio, or more likely,
how much volume that particular sound will have in each
loud speaker. This is both a science and an art.
A lot of the work in this field was centered
(21:18):
around music, and music can contain a wide range of
frequencies and tones. Imagine an orchestra. You have instruments that
primarily create lower frequencies, like lower pitches. You've got tubas
and basses and cellos. Each of those instruments, while creating
notes that might be in the same general range, have
(21:40):
distinct sounds. A tuba and an upright bass do not
sound the same. In other words, then you've got instruments
that center on some of the higher frequencies, like flutes
and piccolos and violins. These also sound different from one another,
and so it became important to figure out how to
not just capture a recording and divide it into channels
(22:04):
to create spatial landscapes, but also how to balance out
the tones so that you don't lose anything in the process.
With the wrong mix, one instrument or group of instruments
might totally overpower another, and it's almost as if those
other instruments were never even present at the original recording,
and so processing recordings and getting the mix just right
(22:26):
became critical. One part of this is called panning, and
it relies on a pan control. In the old days,
you would use a mixing board with physical controls on
it to control the pan. The pan determines how much
signal from each input is sent to each channel. These days,
many audio producers work with digital audio workstations or DAWs,
(22:51):
and with a DAW you also control panning. You can
pan either mono or stereo tracks. Most DAWs will let
you convert one type of track into another, splitting a
mono into stereo or a combining stereo into mono. For
certain types of audio, like mini podcasts, the default is
(23:11):
to go to mono. It can be a little disconcerting
if you record and publish a podcast in stereo. Many
years ago, when I first started recording large nerdron collider
with my friend Ariel. I accidentally recorded and published several
episodes in stereo, which meant all of my audio was
in one channel, like the left channel, and all of
(23:33):
Ariel's audio was in the other channel, the right channel.
So it's like I was talking into your left ear
and Ariel was talking into your right ear, which was
very unsettling. I eventually figured out what I was doing,
and I began mixing our recordings into a mono track
to avoid that problem. And with some early stereo recordings
(23:54):
you can hear examples of problems like this. It's frequently disconcerting.
There are records of songs in which all the instrumentation
is on one side and all the vocals are on
the other side. Now, that might have been done purposefully,
but it was often a sort of heavy handed approach
to stereo. There are times an artist might desire that
(24:16):
specific effect, but other times the desire was to be
a bit more creative with stereo, and you might have
a track in which the vocalist is on the extreme
right of part of the recording than on the extreme left.
Later on, the Beatles A Day in the Life actually
falls into that category. Or you might want to create
a rich soundscape in which there is a sense of
location for all the sound maybe not something that is
(24:40):
explicitly communicated to the listener, but is an important representation
of the performance. So how about we play around with
some post processing panning to create a three dimensional experience.
My producer, Tari, who is a superstar here at iHeart,
is always to the success of this show. But in
(25:02):
a moment, she's going to take over the experience of
what this show sounds like to you, the audience. And
I'm going to do something I've always wanted to do
in three D audio. I'm going to give you a
little Shakespeare. This piece is the prologue to Henry the Fifth,
one of Shakespeare's company Designated the chorus implores the audience
(25:24):
to use their imaginations to augment the production of the
play itself. And so as you listen to this piece,
imagine you are seated on a stage with the chorus
walking around you, explaining your role in creating the theatrical experience. Now,
I admit I'm cheating a little bit here, because the
(25:45):
whole point of this passage is to say that theater
is incapable of creating an exact copy of the story
of Henry the Fifth and England's battles with France. But
you also have to remember I'm a former English literature major,
and I never get to do Shakespeare. So here we go,
headphones on, Oh, for a muse of fire that would
(26:10):
ascend the brightest heaven of invention, a kingdom, for a stage,
princes to act, and monarchs to behold the swelling scene.
Then should the warlike Harry, like himself, assume the port
of Mars, and at his heels leashed in like hounds,
should famine sword and fire, crouch for employment. But pardon, gentles,
(26:36):
all the flat, unraised spirits that have dared on this
unworthy scaffold to bring forth so great an object. Can
this cockpit hold the vasty fields of France? Or may
we cram within this wooden o the very casks that
did affright the air at agincour pardon, since a crooked
(27:03):
figure may attest in little place a million, let us
ciphers to this great accompt on your imaginary forces work.
Suppose within the girdle of these walls are now confined
two mighty monarchies, whose high upreared and abutting fronts, the
(27:26):
perilous narrow ocean parts asunder, peace out our imperfections with
your thoughts into a thousand parts, divide one man and
make imaginary puissance. Think when we talk of horses, that
you see them printing their proud hoofs in the receiving earth.
(27:47):
Fortis your thoughts that now must deck our kings, carry
them here and there, jumping over times, turning the accomplishment
of many years into an hour for the which supply
admit me chorus to this history. Who prologue like your
(28:09):
humble patients, prey gently to hear, kindly to judge our play.
So for that recording, I went into our studio at iHeart,
and I spoke into a normal studio microphone. All the
manipulation had been done in post production, which is an
effective way to achieve that three D audio sound, but
(28:31):
it does require a lot of work on the part
of the producer. But the three D audio I did
at the top of this episode was done in a
different way. I used a special microphone. When we come back,
i'll talk a bit about that technology, and we'll learn
about some companies that have produced specialized equipment for the
purposes of three D audio. But first, let's take another
(28:55):
quick break. While some engineers and artists experimented with binaural
recordings for a while, it wasn't until nineteen seventy eight
that the first pop record using binaural recordings came out.
(29:15):
It was Lou Reed's Street Hassle. Listening to that album
with headphones on is pretty cool. To achieve the effect,
studio engineers took a mannequin head and installed a microphone
at each ear and use that to record sessions. A
company called Delta Acoustics put the system together with Manfred
Schunck supervising. Reed made a couple of other albums in
(29:39):
binarural audio. One was the Live Take No Prisoners album
and the other was The Bells. Other bands would experiment
and recorded binarl as well. The Rolling Stones did it
for their album Flashpoint, which was a concert recording of
some of their big hits and rarities. Pearl Jam record
a studio album called Binaral, recorded fittingly in Binarl. The
(30:04):
tech used to record these albums changed slightly, but it
was still based on the same underlying principles. I think
it's pretty widely understood that our ears receive sound in
the form of vibrations through a medium such as the air,
and then through interactions with the ear drum and the
cochlea and special nerves sending information to the brain. We
(30:24):
interpret those vibrations as sound in a very simple way
of looking at it. Sound comes into our ears. But
did you know our ears also generate sound, Because they
totally do. It's called autoacoustic emission ORAE. Now. To get
into OAEs, how they work and their role in stuff
(30:47):
like medicine is beyond the scope of this podcast, and
more importantly, way outside my general expertise. But it is
true that a very sensitive microphone inserted into the ear
canal of a person with hearing will pick up spontaneous
autoacoustic emissions or soaes. Now, most folks can't detect these sounds.
(31:12):
They tend to be at very low frequencies that dip
below human perception, and they are usually at very low amplitudes,
so they're pretty quiet. But in some cases people might
actually hear the sounds generated within their own inner ears
and experience it as tenetists. I'm one of those people,
(31:36):
yay me. Now, The reason I bring up that fact
that the inner ear can be not just a receptacle
for sound, but also a generator of sound. Is because
an inventor named Hugo Zucarelli used that as the basis
for a system he called holophonics. His idea was that
(31:57):
our hearing isn't a passive thing. That the inner ear
generates signals that interfere with the incoming audio signals, and
the resulting interaction between the sounds made by our ears
and the sounds coming into our ears plays a part
in sound localization. Now, long story short, Zucarelli's hypothesis doesn't
(32:20):
have a lot of support in the broader scientific community. However,
Zucarelli's equipment could record and reproduce sound in a really
interesting way. It's just the whole interference angle of what
was going on seemed inconsequential. Zucarelli used microphones to stand
in for human ears, spaced apart so that a sound
(32:42):
from any given direction would reach one microphone before the other,
and the amplitude of the signal would depend upon things
such as the distance between the microphone and the origin
of the sound, as well as the angle at which
the sound waves would reach the microphone. Zucarelli made a
bunch of different recordings to demonstrate this technology, something called
(33:02):
the Shaking Matchbox recordings, because that was one of the
sounds he actually recorded using this system. Whether his underlying
hypothesis was correct or not, the recordings were effective, and
Zucarelli's approach created a way to make really localized audio effects.
That's essentially what was going on with the Disney sound stations.
(33:24):
Some of the microphones used by recording studios even resembled
a human head, with microphones literally placed where the ears
should be, and that also plays a part in recording
a sound accurately so that the playback will seem as
though you are really there as you listen to it.
Beyond just the fact that our ears are on opposite
sides of our heads and the sound will reach each
(33:46):
ear at different times and amplitudes, other factors also shape
the nature of the sound. We perceive the shape of
our heads, the density of our noggins, our sinuses. All
of that affects our perception of sound. Collectively, we call
all of this head related transfer functions or HRTF. The
(34:08):
technology of holophonics systems and later binural microphones attempts to
replicate the experience of hearing hyperlocalized sounds through the application
of HRTF. But this process is incredibly complicated and it's mathy,
so I'm not going to go into deep detail, which
(34:30):
is good because I would likely mess up the explanation. Also,
it's important to acknowledge that every person is different, which
means there is no universal solution toward creating the perfect
binaural recording that will convince every listener that they are
hearing sounds coming from ultraspecific directions. You kind of have
to go more general to get a good response, but
(34:53):
the more precise you try to get, the more the
results will only work super well for a specific person
you know who whatever it was modeled for, and not
working quite as well for anyone else. For many years,
the microphones used to create binaural recordings in studio were
prohibitively expensive and far too complicated for the average consumer.
(35:17):
You would occasionally find binural recordings, such as the one
at Disney World, but these were pretty rare and very specialized,
and only big companies like Disney could afford to do them. However,
over time, companies began to develop microphones that fell more
into the range of the prosumer, with some consumer level
(35:37):
solutions thrown in there as well. Today there is a
range of microphones one can use to create three D audio.
The microphone I used earlier in this episode is a
three deo binural mic or a three D if you prefer.
You may have seen one of these if you watch
a lot of ASMR videos. They are very popular. The
(36:00):
microphone looks like a horizontal bar with two silicone ears
attached to either end of that bar. The ears are
spaced apart to mimic a typical human heads width. The
three D doesn't have the mass of a head, it's
just that bar in the ears. It doesn't have the
sinus cavities or anything like that. So it is not
(36:22):
a perfect simulacrum of a person's auditory system, but it
gets the job done. That style of microphone typically retails
are around four hundred dollars, so it's a little bit
on the pricey side, but it kind of falls between
consumer and prosumer. However, you can achieve similar results using
(36:42):
totally different microphone setups. They typically require XLR microphones that
connect to a recording device that can accept multiple inputs
recording each microphone to its own audio channel. It's possible
to use two normal microphones and space them apart from
each other and create a binaural experience, though it might
(37:03):
take some experimentation to get the spacing and gain levels
just right so that it all feels natural. Or of course,
you could just do it in post, but like I said,
that relies heavily on a ton of work on the
back end of things, and ASMR artists are not the
only ones using binaral audio. It's also useful for stuff
(37:25):
like virtual reality experiences and video games. Sound is a
powerful element that contributes to a sense of immersion, and
in some games it's critically important. For example, you might
play a first person shooter game like Player Unknowns Battlegrounds,
and you really need to use your ears to figure
out where other players are in relation to where you are.
(37:48):
Not doing so severely reduces your chances of making it
through the game. If you'd like to learn more, I
would recommend seeking out Old Tech Stuff episodes about surround sound,
which relates to this topic quite a bit, and also
our episodes about audio compression, as the process is designed
to compress audio. Tried to take the psychology of perception
(38:10):
into account. It's all fascinating stuff. As for three D audio,
I figure i'd leave you all with a little bit
of horror because three D audio works really well to
immerse a listener into a world, and it is particularly
well suited for tales of terror. Some of my coworkers
used it to great effect in a series called Thirteen
(38:33):
Days of Halloween, which we published last October, and so
here is a little excerpt from the show they produced.
Speaker 4 (38:43):
Ah, look at all the fun we're having in here.
I just knew you two would get along swimmingly. Oh no,
come with me, Surin.
Speaker 2 (38:55):
We'll catch up with you later. Dearhart is a truly
sweet young man. I've been attempting to persuade him to
see the good doctor about his cough, but he'll have
none of it. Maybe you could be of service in
that department. He really seemed to like you. Now, there
(39:16):
are hundreds of rooms here of the Hawthorne, but this
is perhaps the very finest, and it just so happens
to be your waters. Was it luck or.
Speaker 3 (39:29):
Fate that placed you here? We'll never know.
Speaker 5 (39:36):
I trust that you'll find everything to your liking. And
if you don't notify me and I will make sure
it is rectified. It's all part of my role here
as the caretaker. You know, your lack of verbal reciprocation
is really breaking down my sense of boundaries. I can
trust you, right of course I care.
Speaker 3 (40:02):
In these coming days, you may notice that Hawthorne manner
has no shortage of oddities. I've witnessed things myself that
strain the belief. But there is one strange legend that
has truly become something of an obsession. Supposedly, somewhere within
(40:24):
these halls there is a hidden doorway. If the tale
of what lurks on the other side is to be believed,
then gaining access would mean a sort of ascension beyond
human imagination, true immortality. I have come to understand that
one of our guests knows how to locate and open
(40:48):
this door. Perhaps what they cannot say to me, they
will happily divulge to you. I have a feeling your
quiet fortitude will lure them into a sense of intimacy.
Speaker 2 (41:04):
It certainly works on me.
Speaker 3 (41:08):
Please make yourself at home. After all, this is it.
There are so many others I cannot wait for you
to meet.
Speaker 1 (41:22):
Well. That wraps up this special episode of tech Stuff.
Several of the iHeart shows are including some binaral audio segments,
and we've got a lot planned into three D audio
space in the days up ahead. I really recommend you
check it out and explore some of the three D
audio recordings that are available online. You know that Disney
(41:45):
one I mentioned, There are actually versions of that up
on YouTube. People have the recordings up. I will say
that when I was listening back, it sounded like the
channels had been swapped. Everything that was supposed to be
in my right ear seemed to be coming through the
left ear. And I made sure that I was wearing
the headphones correctly. That's an important point, by the way.
(42:05):
If you're not wearing your headphones with the proper phone
over the proper ear, it's very disconcerting. I double checked
I was doing it correctly. Everything still seemed flipped and
the effect was not nearly as impressive as it was
when I went back to Disney. But I should also
add the Disney version incorporated some stuff that headphones just
(42:26):
can't do, stuff like a blower behind each person's back,
so that when you're getting a haircut in that sequence,
the hair dryer would actually blow air on you, so
that would add to your sense of immersion as it stands.
For me, if I'm listening to a very well recorded
three D audio setup, then if someone speaking quietly into
(42:51):
my ear, it's as if I can feel it, because
we have to remember sound when it gets down to it, Really,
that's just vibration. Those vibrations include fluctuations and air pressure.
So if you are listening to someone talk into your
ear through a speaker, you will feel it because those
are fluctuations in air pressure. It's not something you're imagining.
(43:14):
You are feeling it. It might be heightened because of
the way the audio is recorded, but it's actually happening
to you. I think three D audio is an incredible technology.
There's a lot more we could say about it, and
not just from the technological side, but the psychological side
and the biological side. So maybe I will do future
(43:36):
episodes that will focus on this more. I hope I
get a chance to play with the three D audio
microphone more. That was a lot of fun. I really
enjoyed doing that. I hope that I get to participate
in some of the three D audio recordings that we
have planned coming up, including some that are delving into
different areas of fiction. I would love to do that. Honestly,
(43:59):
I would love to do a full three D audio
version of a Shakespearean play. It is something I have
really wanted to do for a long time. I'm not
even talking about necessarily being in it, although it would
kill me not to be, but to be able to
experience a three D audio version of one of Shakespeare's plays,
(44:19):
to me, would be unbelievably amazing. So if you think
that's interesting, you should write to iHeart and let them know,
because I think it would be great. I wouldn't mind
working on something like that and let me know what
play you think we should do. Honestly, I'm thinking like
much ado about nothing. I think a comedy might be fun. Well,
(44:42):
I hope you enjoyed that episode from twenty twenty one
how three D audio works. I think three D audio
can really be fascinating and really immersive. Like I still
really love ASMR videos that do the ear to ear
stuff and use a lot of spatial audio. Well, it's
not as common now like that was like a big
(45:03):
thing many years ago when ASMR was first really starting
to take off. But these days I seem to see
a lot more things that are based off specific what
they call triggers, specific sounds, or specific effects, but less
the ear to ear stuff, which is the evolution of
the field. But it makes me miss the really cool
(45:24):
three D audio things that make you feel like you're
in an actual space with people really moving around you.
To me like, that's just an effect that I can't
get enough of. So that's kind of why I wanted
to go back and revisit this episode. I'll be back
on Friday with a new episode about tech news. We'll
find out what the heck happened on the week of
Memorial Day. I'm recording this the week before, so I
(45:47):
don't have any clue. As we've established many times, I
am not good at predicting the future, so I'll find
out when you all do. So I hope you are
having a great week, and I'll talk to you again
really soon. Tex Stuff is an iHeartRadio production. For more
(46:10):
podcasts from iHeartRadio, visit the iHeartRadio app Apple Podcasts for
wherever you listen to your favorite shows. This episode was
brought to you in iHeart three D Audio. To experience
more podcasts like this, search for iHeart three D audio
in the iHeartRadio app. Thank you to our sponsors, Audible,
(46:33):
The Conjuring, The Devil Made Me do It, Rated R,
and World of Warcraft.
TechStuff News
Hosts And Creators
Oz Woloshyn
Karah Preiss
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