Free tool
Mic test
Speak once. See if this browser can hear you. Then download Nimva for Mac dictation that stays on your machine.
Press start, then speak.
Audio stays in this browser tab. Nimva does not receive it.
Your mic is working.
Nimva uses that same permission on Mac—plus silence-while-dictating so background audio does not drown your voice.
Download Nimva for Mac7-day no-card trial on sign-in. About 200 MB.