To listen to language B of a dual language program, click this button. To listen to language A of a dual language program, click this button. To set the treble, drag the lever left or right. The marks indicate the usual setting. To set the bass, drag the lever left or right. The marks indicate the usual setting. To set the sound balance, drag the lever left or right. The marks indicate the usual setting. To listen to stereo sound (when it’s available), click this button. To listen to the Second Audio Program sound channel (SAP) when it’s available, click this button. SAP is sometimes used to broadcast a program in a second language. To listen to monaural sound, click this button.