Binaural Recording

Please check this page in the next week - I hope to have it finished soon!

My own approach, and two older binaural headphone-microphones from JVC and Aiwa.

Robin Whittle     14 August 2003

To the rest of this First Principles site for all sorts of things, including the world's longest Sliiiiiiiiinky, various show-and-tell things, Indian Classical Music, electronic and software synthesis of music etc.

Binaural microphones can be scary if you think about their eyes, so Florian often goes incognito


Binaural recording uses a dummy head - or perhaps a real person's head - with a microphone in each ear canal.  This means that the recorded signal is processed by the shape of the head and outer ears (pinna) in much the same way as would be heard by a person in that position.

Sound travels at 331 metres (1130 feet) per second.  The brain uses three major facets of the signal from the ears to determine the likely direction from which the sound is being heard:
  1. Loudness differences between one ear and the other.
  2. Time delay differences. 
  3. Frequency response differences between the ears and differences from what the brain thinks is the natural frequency spectrum of the sound. 
The exact way this is achieved is a matter of ongoing research, but the brain is clearly highly adept at deriving directional information about sounds based on some very fine details, such as small fractions of a millisecond time differences, and subtle differences in frequency response which result from the wavefront entering the pinna and ear canal from various directions - various elevations and azimuths.

Trying to create such responses in software is very difficult!  But its relatively easy to make a dummy head, with some ears, and pop some small microphones in the ear canal.

The result is a recording which sounds really good, open and spacious on loudspeakers, but which as very strong spatial cues when listened to on headphones.