Chapter 4: Audio

There are 3 main types of audio that we need to cover:

• Mono
• Stereo
• Surround Sound

The key principles are these:

Mono means one. One piece of audio is recorded and then played back through the speakers. If you are watching your TV at home and it has a speaker at either side then they will both play the same sound at the same time. Simple!

Both the Left and Right channels are identical

Stereo means two. This time we have two separate tracks, or channels. The left and the right. They might be very similar for most of the time, but the sound of approaching footsteps might be slightly louder in the right channel, making it sound like someone is just slightly to our right. The footsteps might be a LOT louder in the right channel, making it seem like they must be way over to the right. Clever sound engineers (or average sound engineers with clever software) can make the sound pan between the speakers so it seems to be moving from side to side.

This time, the left and right channels are different

Surround sound takes your left and right, and adds front and back - making four speakers at opposite corners. This way we can position the sound quite accurately to make us think it's coming from a very specific location. Cinemas always use surround sound, and more and more front rooms are being equipped with surround sound systems.

Of course creating an effective surround sound audio track, even a stereo one, is not an entirely simple matter. Most amateur or beginner film-makers simply stick to mono audio for its simplicity, but at least you know what the terms mean now!

Reproduced with kind permission from Mark Clarkson, from the originial source