When referring to raising the "TV voice," we'd say "turn up the volume" or "turn up the sound." An abbreviated form is simply to bark at the person holding the remote control: "Turn it up!" (Likewise, if you want the sound lowered, you'd say "Turn it down.")
If you want the sound muted, you'd ask the person with the remote to "Hit the mute" or "Can you mute it, please?" Example: the television is on very loudly, and the telephone rings. You turn to the person holding the remote control and say "Can you mute it, please, I have to answer the phone."
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