In order to hear sound during the playback of an animation, the playback speed must be set to a constant rate so that Maya can determine how slowly or quickly to play the soundtrack.
Now when you play your animation, you will here the audio file that you imported.
Scrubbing can be useful for locating a specific time at which a particular sound or portion of sound begins. For example, if your soundtrack includes, “Hi Dave,” you may want to locate the exact frame at which the “D” sound begins so you can synchronize the character’s mouth forming a “D” sound with the soundtrack.