Data representations for speech data I'm interesting in knowing more about different kinds of data representations that are used for speech data. I know of FFT, but not any others. More precisely, I have the 3 following questions.


What data representations for speech data?
What is considered the most 'raw' representation?
How has the use of different representations evolved over time?


Simply answering 1 or 2 of the questions would also be great. Thanks.
I have seen people use MFCC coefficients for speech related analysis.It is a  done using filter banks and logarithmic scales for representing speech.