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Silence one clip, not the take
Mute is per clip in QCam. Kill the audio on the one shot with the cough or the traffic, and the neighbors keep their sound and their sync.
Fence the noisy part
Split the take where the unwanted sound lives, so the noisy stretch is its own clip. The playhead is standing on it as soon as the split lands.
Tap Mute
Tap Mute and the clip under the playhead goes silent. While you stand on a muted clip the toolbar item reads Unmute, ready to bring the sound back with one tap. Every other clip keeps its audio, untouched and in sync.
Muting is an ordinary edit: undoable, reversible, and the original recording keeps its sound forever.
Fence the noisy part
A cough, a truck, a bumped mic: fence it, mute it, move on. The rest of the take never knows anything happened.