Signal processing for audio and speech I have started learning about signals and I am interested in sound signals.

There are some questions that I need to resolve. For example in music, difference of notes like 'sol' and 'la' are about difference in frequency. But which features of signals reveal differences between piano and guitar. What sound features distinguish between two different syllables?

Can you give me a good learning source about audio processing?
In line with a previous similar question here are my suggestions:

There are so many nice books but I believe you should first have a look at the science of sound from Rossing for getting the most broad view on the subject.

Then you can look at the following books , each dealing with a particular dimension of the problem:

1- Acoustics_BERANEK

2- Elements of Acoustical Engineering_OLSON

3- Music, Physics and Engineering_OLSON

4- Art of Digital Audio_WATKINSON

5- Audio Engineering_SINCLAIR

6- Digital Audio Effects_ZÖLZER

7- Digital Audio Signal Processing_ZÖLZER

8- Fundamentals of Acoustic Signal Processing_TOHYAMA

9- Audio Signal Procesing and Coding_SPANIAS

10- Audio Programming Book_BOULANGER

11- PsychoAcoustics_ZWICKER

12- Acoustics and PsychoAcoustics_HOWARD

EDIT:
I'm sorry that I've forgotten to mention about books on speech processing, so here you can find a list:

1- Speech and Audio Signal Processing_GOLD

2- Speech and Hearing for Communication_FLETCHER

3- Discrete Time Processing of Speech Signals_PROAKIS

4- Fundamentals of Speech Recognition_RABINER

5- Introduction to Digital Speech Processing_RABINER