Wiktionary
vb. (context transitive English) To restore the sound output (on a speaker or other audio device), having previously muted it.
Usage examples of "unmute".
A fresh flash of lightning lit the roiling waters and unmuted thunder assailed her exposed head.
He unmuted and then listened with fascination as the newscaster described a disastrous fire at Fort Gillem, just southeast of Atlanta, Georgia, with die complete destruction of the Atlanta DRMO.
Some careless word, some unmuted compassion in voice, the stealthy wrapping of a pair of boots, the unaccustomed shutting of a door that ought to be open, the removal from a down-stair room of an object always there--one tiny thing, and he knows for certain that he is not going too.
She waved and hurried up the stairs, unmuting the t-jack as soon as she reached the next level.