The sound is an essential component of multimedia, and due to the needto be used in many life applications such as television broadcasting andcommunication programs, so it was necessary for the existence of audio signal processing techniquessuch as compressing, improving, and noisereduction. Data compression process aims to reduce the bit rate used, by doing encoding information using fewer bits than the original representation for transmitting and storing. By this process,the unnecessary information is determined and removed, that means it gives the compressed information for useable compression, which we need as a fundamental, not the minutest details. This research aims to study how to process sound and musical signal. It's a process that consists of a wide range of applications like coding and digital compression for the effective transport and storage on mobile phones and portable music players, modeling and reproduction of the sound of musical instruments and music halls and the harmonics of digital music, editing digital music, and classification of music content, and other things.