哑 (yǎ): немой

When he was a child, he had a serious illness; after he recovered, he became mute and could no longer speak.

Some people are born deaf and mute, but they can still communicate with others using sign language.

The girl who usually loved to talk suddenly went mute; she just lowered her head and didn't say a word.

He lost his voice; the doctor told him to talk less, drink more water, and rest for a few days.

No matter how I asked him, he just kept silent in a hoarse voice, as if something was troubling him.