You can solo a track, silencing all tracks that are not also soloed. Soloing tracks is useful when you want to work on a track individually, or work on a few tracks, without hearing the other tracks in the project.
The first time any track in a project is soloed, a large Solo button 
appears in the area above the track headers. You can quickly unsolo or resolo all soloed tracks using this button.
Click the track’s Solo button in the track header.
The Solo button turns yellow, and the Mute buttons of all unsoloed tracks flash blue. Click the button a second time to restore the track to its previous state.
Click the Solo button in the control bar, then click the track.
Do one of the following:
Click-hold a Solo button in a track header, then drag the pointer up or down.
The Solo buttons of all swiped tracks switch to the same state.
Press and hold Shift while the Solo button in the control bar is active, then click the names of the tracks you want to solo.
Click the Solo button in the area above the track headers.
To resolo all previously soloed tracks, click the Solo button above the track headers again.