What is Stereo?
The term stereo can be applied to both audio and vision (sound and pictures).
Audio stereo means sound which is divided into two separate channels. These two channels are played back simultaneously via separate speakers. The effect is to create a fuller sound, and provide the ability to mix certain sounds between channels.
Humans normally hear the world via two ears so providing dual sound sources is more realistic, although it does not fully replicate the way we hear.
Some common examples of stereo sound include:
- Spreading the instruments in a music track from left to right. Often the tom-toms in a drum kit provide great stereo panning, as do some guitar effects.
- Following the action in a video, e.g. a car speeds across the screen as the audio pans with it.
Visual stereo means two separate images of the same subject, taken slightly apart, to simulate the 3-D view of two human eyes. Stereo images can be reproduced in a variety of ways, the most well-known being anaglyphic reproduction (which requires red/green, red/blue or red/cyan viewing glasses). For more information see stereoscopic photography.