Echo and Reverberation in Audio When Playing in the Timeline or Produced File

Problem

I am hearing an echo or reverberation in my audio when playing on the timeline or produced file.

Solution

This is caused by recording both system audio and another source (microphone, stereo mix, etc.) simultaneously. These tracks can get slightly out-of-sync and cause the echo.

Camtasia Recorder:

If recording system audio only, make sure System audio on has a green button marking it as active and the Microphone icon has a grey slash through it.

If recording your voice (microphone) only, make sure System audio has a grey slash through it and Microphone has a green button marking it as active.

You can also fix existing recordings by deleting one of the audio tracks in the timeline.