TapNoiseAn orange privacy indicator means a microphone is in use. Open Control Centre to inspect the activity information available on your macOS version rather than guessing which application is listening.
Look for a plausible source
A call app, Dictation, a recorder or an input-level meter can activate the microphone. Close the feature you no longer need and check whether activity ends.
The dot is an activity signal, not a universal mute button. A call app may remain connected to the microphone while its own mute control stops sending your voice to other participants.
Separate permission from activity
Microphone permission allows an app to access input; it does not mean that app records continuously. Conversely, changing an output device does not revoke microphone access.
Review System Settings › Privacy & Security › Microphone if you no longer want a particular app to use it. If the Mac is managed by an organisation, some controls may follow its policy.
How this relates to TapNoise
TapNoise checks whether a microphone is active so it can pause its own sounds. It does not record microphone audio for that decision. An unexpected quiet period may therefore be explained by Dictation or Sound settings rather than a meeting.
For input selection, see choosing a microphone. For intentional audio suppression, read why typing sounds stop during calls before disabling a useful protection.
Sources: Apple’s menu bar indicators, TapNoise microphone behaviour.