If you are playing GTA vice city, then they are available in no sound version.
Goto your Drive (C:\, or D:\) C:\program files\rockstar games\ and right click on your game folder and press properties. If the size is less than 1GB then you probably have the no audio (ripped) version. Audio files in gta VC cover around 900mb data. if the size is greater than 1gb(around 1.4gb) then you have propably turned off the audio in your game settings