# Can you represent an audio signal in any other domains besides time and frequency?

Maybe a stupid question, but if there is a time-domain representation of audio signal, and also frequency-domain, so is there any other domain that signal can be represented in?

• Cepstrum is very useful for some applications. – Serge Apr 7 '13 at 13:59

Basically it's all about breaking down the information into several 'bits'. The actual audio signal is a time varying 'value', however often it is useful to consider it in a different form. As an analogy, consider the number 256: depending on what you're doing with your numbers, it might be useful to treat the number as 200 + 50 + 6, or 16 + 240, or 16*16, or maybe as 2^8; there are an infinite number of ways to treat the number, and which one you use depends on what you're trying to achieve.