Audacity 4 documentation · Primary-source explanation; examples are illustrative. Instructions are based on publisher guidance; a UK IPTV account was not tested on this platform.
Decide whether the duration may change
Audacity documents Truncate Silence as detecting sufficiently quiet, sufficiently long passages and shortening them. That is a timing edit. If a narration file must remain aligned with an already edited video, removing a pause can move every later spoken event relative to the picture. First decide whether the task is to tighten an independent audio programme or preserve an existing audiovisual timeline.
Use an event after the edited pause
For an original example, a demonstration recording contains a visible action at minute five and a long quiet interval earlier. If that earlier interval is shortened by several seconds only in the audio, the minute five action can lose its corresponding narration timing. Mark a recognisable event after the proposed edit and compare its position before and after processing. Do not judge synchronisation from the opening sentence alone, since that sentence precedes the changed region.
Keep related microphones aligned
The current effect offers independent processing of selected tracks. Leave that choice off when separate microphone tracks belong to the same conversation; independent decisions can remove different intervals from each. Also review the threshold against quiet wanted speech, rather than equating a low waveform with disposable material. Preserve an original version and inspect the resulting duration and later cues. When timing must remain fixed, choose an editing method which preserves the required interval instead of silently substituting a shortened recording.