In a world that seems to be ever noisier, using more noise to improve matters might seem like a strategy that is doomed to failure. However, it is a characteristic of human hearing that one sound tends to mask other sounds, and this can be used to good effect in counteracting otherwise obtrusive sounds.

This wave effects project is a simple battery powered device that can be used with headphones or used to feed a spare input of a hi-fi system. It does not provide results that are as convincing as units utilising digital recording techniques or sophisticated synthesiser circuits, but it is quite good for a device that uses just a handful of inexpensive components. It is simple to build and is well suited to beginners.