How Dolby Headphones and Holophonic Sound works

How can you fake surround sound with just the two speakers of headphones. The concept behind it is simple. You only have two ears, yet you can still determine the direction of a sound. The shape of your ears affects and alters the sound depending upon the direction of the sound.

To simulate this effect Dolby and Holophonic uses a dummy head with well scupted outer ears and a microphone in each ear. A tone is beeing emitted from one part of the room and the results are recorded and analysed by a computer. This is repeated with tones beeing emitted from all over the room. The comuter then compares all the recordings.

The properties of a sound emitted from a specific place in the room can then be applied to any sound, giving it a place in 3D spce relative to your head.

This only works if you have headphones on, because the sound needs to be projected into your ears without disturbance of your outer ears. The closer your ears are in resemblance to the dummy's ears the more accurate the effect will be.

/Joel