Duen Hsi Yen's Binaural, 3D, Holographic Sound Page!

For your listening pleasure. 1M = 1 minute of recording! MPEG Audio (stereo) @44.1KHz
16-bit 160-kbps layer II using the Mpecker Encoder. Must use Headphones!

2 running dogs/1.2M ©1984              sparkler/2.4M ©1984
barking dogs/0.6M ©1984                birthday party/1.1M ©1985    
Haydn Divertimento/Cello/0.7M ©1991    Dvorak Op.104/Cello/1.7M ©1986
Prokofiev Prelude/Harp/0.9M ©1983
match/0.1M/mpeg test                   bag/0.3M/

Web pages having binaural sound clips:

Binaural Source         Holophonics           Lake DSP                                
Timothy Read            David Wareing         Phil Brown               
SRS Labs                NuReality             Intel 3D RSX                     
Univ. Wisconsin         Talking Chair         Sensaura          
3D Sound                Virtual Audio         Spatializer                 
Focal Pt 3D             Crystal River Eng.    Qsound       
SonicStudios            LaMarchina            Gordon Hempton  
HiFi MP3 Sounds         Tim's Favorites       SoundBlaster
Virtual Listening       David Robinson        vOICe
Human Machine           Vizuete               HUT VMRL 
Ripple Pitch*           ODEON   
  

MPEG Sound Players

Macintosh   SoundApp   MacAmp   Mpecker  MPEG/CD   Maczilla 
Windows     MaPlay     WinAmp   Xing     AMAPlay   CoolEdit  
All Others  Mpeg.org   IUMA     MP3      RealAudio

MPEG Encoders

Macintosh   MPecker    MPEG/CD  BarbaBatch

Here are some binaural recordings I made, as well as links to other webpages having 3D sound so you can judge the various technologies yourself. The true test is in the hearing! Normally, we can spatially hear sounds, be they left, right, up, down, front, back, near or far. Binaural recordings attempt to capture all the information necessary for this effect. When done successfully, one experiences outstanding sonic clarity with the auditory image perceived externally out in three dimensional space, just as if you were there in real life.

One way to make binaural recordings, is to install a pair of microphones into a dummy head modeled after a real human head, one located in each ear. Notable examples include: Fritz, KEMAR , Aachen - Head, B&K 4128, and Cortex. The more exact the replica, the more realistic is the binaural recording. Or you can use your own head and insert probe or miniature microphones into your own ear canals. Different pinnae sound different, and indeed certain ear shapes are better in capturing 3D sound than others. So, who has the golden ears? Just like imperfections in the lens of the eye can lead to distortions in spatial vision, similarly, imperfections in the shape of the external ear can lead to ambiguities in spatial hearing. Of course, your retina and inner ear must be in good working order too, for accurate spatial perception. Test your high frequency limit here.

Synthesizing 3D sound digitally is of great interest to the Virtual Reality industry. Basically, this is how it's done. A computer model representing the acoustics of the human head and pinnae can be measured and is called the head related impulse response. Digitally convolving a sound with this response synthetically creates binaural sound. Again, the closer the computer model is to your own head acoustics, the more realistic is the binaural sound. Actually, full realism and clarity requires the modelling of the complete environment, such as room reflections or the acoustics of the concert hall, and even modelling the directional characteristics of each sound source. Computationally, very intensive! You can create your own binaural sounds from monaural sounds using Tom Erbe's SoundHack program for the Mac, which uses Durand Begault's HRTF measurements for NASA's ASAD. I just made this helicopter.mp2/0.2M fly around using Phil Brown's monaural helicopter sound.

To experience the 3D effects, you must replay binaural recordings over headphones/earphones. This is to insure the left ear gets only the left ear signal, and the right ear gets only the right ear signal. When binaural recordings are played over loudspeakers, there is the problem of cross talk. When the left loudspeaker plays a sound, the listener hears this in both ears, and similarly for the right loudspeaker, resulting in garbled 3D. Afterall, if a sound source is moving front to back, or up and down, you are not going to hear these effects via a conventional stereo sound system, which is one dimensional (left-right). One way to make binaural recordings playable over loudspeakers is to preprocess the signals via a transaural cross-talk cancellation scheme: One of the most amazing of these systems is the new stereo-dipole being developed at the Institute of Sound and Vibration Research and Tokyo Denki University! I am currently writing a transaural 3D holographic sound page to complement this one.

If your browser has Apple QuickTime (3.0 preferred, but 2.1 or greater will work), it can be configured to automatically play the .mp2 formatted sound files. Or you can download them and use one of the listed players. For two comprehensive listings of web pages, see either the 3D Audio Page or the Ultimate Spatial Audio Index.

*This is not binaural, but blind persons use ripple pitch to echolocate distance. Ripple pitch can also be clearly heard on the sparkler recording. You can hear a rising pitch as the sparkler gets closer to the ground. The effect is otherwise known as comb-filtering, or phasing/flanging, as when an jet plane takes off.

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Last updated 29 September 1999

Copyright © 1998-99 by Duen Hsi Yen, All rights reserved.

E-mail: yen@noogenesis.com

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