A Layman’s Guide To 3D Audio


The 3D Audio/3D Sound/Binaural Sound space is heating up. With many companies entering the sphere, let me provide a plainspeak FAQ to get you up to speed. 

What is 3D Audio/3D Sound/Binaural Sound?

It's sound recorded identically to the way our ears normally experience it. The result is an audio file that, when played back on headphones, allows you to feel like you're there.

Binaural sound is not to be confused with conventional stereo sound. Stereo does not factor in the natural ear spacing or "head shadow" of the head and ears. These things happen naturally as a person listens, generating their own ITDs (Interaural Time Differences) and ILDs (Interaural Level Differences). Stereo recording is not capable of capturing these ITDs and ILDs.

http://www.freesoftwaremagazine.com/articles/understanding_surround_and_binaural_sound

http://www.freesoftwaremagazine.com/articles/understanding_surround_and_binaural_sound

For true binaural results, an audio recording and reproduction system chain traveling from a microphone to a listener's brain should contain one and only one set of pinnae (preferably the listener's own) and one head shadow.

Listen with headphones.

How does wind noise effect binaural recording?
Wind effects binaural recording the same way it effects standard microphones. Wind noise occurs during outdoor use when wind hits the microphone diaphragm directly. The stronger the directivity of a microphone, the more prone it is to pop and wind noise. An omnidirectional microphone is barely susceptible, whereas hypercardioid or figure-of-eight microphones are very sensitive to pop and wind effects. Pop and wind noise can be muffled effectively by a foam wind shield (pop shield).

Most binaural recording systems utilize omnidirectional microphones, which must be protected against wind noise despite their low susceptibility.

What file format is binaural sound recorded in?
A binaural recording is identical to a stereo audio file. Which means it's a two track audio file. The two common types of audio are files are mono (one channel) and stereo (two channel). Ever heard a piece of music where you can detect specific instruments in different ears? That's stereo. Ever heard a piece of music where every instrument is playing out of both ears? That's mono, you can't sense any directionality. 

Either of these file types can be saved in whatever format you choose (.wav .mp3 .aiff etc.), which means a binaural recording too can be saved in whichever format you choose. 

Can I play binaural sound on other speakers / headphones?
Once recorded, the binaural effect can be reproduced using any regular set of headphones or a dipole stereo. It does not work with mono playback, nor does it really work with loudspeakers as the acoustics of this arrangement distort the channel separation via natural crosstalk (an approximation can be obtained if the listening environment is carefully designed by employing expensive crosstalk cancellation equipment.) See Edgar Choueiri's brilliant BACCH System.

If Binaural Sound is recorded wirelessly, is there latency?
That heavily depends on the transmission device one is using. Most bluetooth audio codecs experience a latency time of around 150ms. This is a problem as humans will begin to detect sound arriving later than an image at around 80ms. However, there are a few Bluetooth chips on the market that use a high quality Bluetooth audio codec which transmits at around 40ms. 

When did binaural first start pairing with video?
If you've been fortunate enough to experience binaural sound, you've probably only experienced it on the listening end. It's difficult to pair binaural sound with video because both formats must precisely reflect the perspective of the recordist in order to function properly. If you were to wear a pair of binaural mics and record with a video camera that is positioned 6 feet above your head, the resulting media would be inaccurate. We need to make sure we are capturing video the way we see it with our eyes in order for binaural recording + video to work together.


WHAT IS THE DIFFERENCE BETWEEN 3DSound, 3DAudio, Mobile 3D Audio, AND Binaural Audio?

Truthfully, they're all the same. The space is so new nobody's quite sure what to call it yet, but at the heart of these marketing buzz words is binaural audio. Binaural audio dates back to the 1880s when French engineer Clément Ader created the Théâtrophone. Since then, binaural recording technology has advanced slowly, but steadily. At Hooke, we like to call it Mobile 3D Audio since we're the only Bluetooth binaural microphone on the market.

After the Theatrophone came AT&T's Oscar in 1933. 

After the Theatrophone came AT&T's Oscar in 1933. 


If 3d audio HAs been around since the 1880s, Why Hasn't it Caught On?

a. The market is tailored and priced for professional CONSUMERS

Current manufacturers of binaural microphones seem to think $7,999 is a justifiable price for two microphones inside a dummy head. True, there is firmware, DSP processing, and acoustic engineering at work here, but the production costs don't justify this markup. If we continue to offer binaural technology at this price point, it will only ever be attractive and available to a niche market. 

Sure, you could record on an ASUS computer and save a few hundred bucks...

Sure, you could record on an ASUS computer and save a few hundred bucks...

B. people aren't going to add another piece of gear to their already gear-intensive lifestyles

On your daily commute, you're probably carrying a smartphone, a computer or tablet (or both), a book, headphones, power cables, make up. The last thing you're going to want to do is add a pair of microphones to that list. 

The Hooke Verse - Our First Product

The Hooke Verse - Our First Product

C. We've never carried a hard drive around with us to record sound. until now.

Your smartphone. It's a hard drive. And it's just waiting for you to record 3D Audio on it. As of 2014 about 2.7 billion people own smartphones (http://bit.ly/LjwToI). That's a lot of computers sitting around, waiting to seamlessly track 3D Audio.

D. field recorders have been seen as the mobile sound recording solution

Field Recorders come at a premium cost with a relatively steep learning curve. They require their users to purchase external microphones to record sound and another device to bounce the field recorder sound to a computer. Think of it as the computer hard drive that our smartphones now posses. It doesn't integrate with video seamlessly and it's still a somewhat cumbersome piece of gear to add to one's lifestyle.

One of the more popular field recorders on the market, the Zoom H4N. Retailing at $199.99

One of the more popular field recorders on the market, the Zoom H4NRetailing at $199.99


who's making 3d Audio devices?

Almost all binaural microphone systems are living in the professional market right now. They require sound recorders to track to, cables, and expensive batteries. But there is some variation in their applications. 

 

The 3Dio Free Space Pro II

proIIBanner.jpg

Music playback? No
3D Audio Recording? Yes
Wireless? No
Wearable/Portable? No
Smartphone Compatible? No
Social Media Integration? No
Requires Field Recorder? Yes
Price: $1999.99


The Neumann KU 100 Binaural Head

Music playback? No
3D Audio Recording? Yes
Wireless? No
Wearable/Portable? No
Smartphone Compatible? No
Social Media Integration? No
Requires Field Recorder? Yes
Price: $7999.99

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Mitra 3D Mic Pro

Music playback? No
3D Audio Recording? Yes
Wireless? No
Wearable/Portable? No
Smartphone Compatible? No
Social Media Integration? No
Requires Field Recorder? Yes
Price: $995.00


Roland CS-10EM Binaural Mics

Music playback? Yes
3D Audio Recording? Yes
Wireless? No
Wearable/Portable? Yes
Smartphone Compatible? No
Social Media Integration? No
Requires Field Recorder? Yes
Price: $134.99

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The Hooke Verse

Music playback? Yes
3D Audio Recording? Yes
Wireless? Yes
Wearable/Portable? Yes
Smartphone Compatible? Yes
Social Media Integration? Yes
Requires Field Recorder? No
Price: pre-order $139.99


Binaural Recording Mic - Otokinoko

Music playback? No
3D Audio Recording? Yes
Wireless? No
Wearable/Portable? Yes
Smartphone Compatible? No
Social Media Integration? No
Requires Field Recorder? Yes
Price: $3,900.00


Andrea Electronics 3D Surround Sound Recording Ear Buds SB-205W

Music playback? Yes
3D Audio Recording? Yes
Wireless? No
Wearable/Portable? Yes
Smartphone Compatible? No
Social Media Integration? No
Requires Field Recorder? Yes
Price: $34.99


What does the future hold for 3d audio?

With the rise of VR headsets like Occulus Rift and Google Cardboard, we're beginning to see a shift immersive experiences. The way we experience video games and movies is beginning to change. The confines of the rectangular screen are rapidly disappearing. With the rise of this experiential playback, 3D Audio too will grow in popularity.

Another main contributor is the rise of the smartphone. With it, we will be capturing more content and listening to more content like podcasts, music, and video on headphones. Perfect for a multifunctional device like Hooke. 

The future is immersive media. Seeing and hearing things the way we see and hear them in real life. 3D audio is here to stay.
 

From One Ear To Another,
Anthony Mattana
Hooke Founder

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