haier L26A16 - Manual (Page 25)

When you need to pay attention to surrounded sounds, or
there is a telephone calling you or there are some guests
visiting you, the sound elimination (mute) function is very
convenient.
Eliminate sound
1
Press the MUTE button on the remote control and "Mute"
type face will display on the lower part of the screen. At this
time, the sound of the TV set is turned off.
2
If you want to recover the sound, press the MUTE button
again or directly press VOL+ button.
Sound Adjustment