Voice-Over, volume issues

[Weef]

For educational purpose I want to make a voice-over but the question is : "1. How can I supress certain passages of the audio track and not mute them?...And 2. How can I merge the spoken with the other audio track??"

[guns1inger]

There are two ways to do this

Audacity has a plugin called Duck (or similar) that takes two audio tracks, and adjust the volume of one to allow the other to be heard over the top. This is an automated process, and seems to work reasonably well most of the time.

The other method is to use an audio or video editor that allows for multiple audio tracks to be loaded side by side, and you you can then manually adjust the audio of the original audio so it hides under the voiceover track. You can do this in Audacity, but I would suggest Reaper (free) or Vegas Pro (if you already have it) because they allow the use of envelopes to adjust volume levels. This is far easier than audacity, as you just set and adjust points on the timeline instead of highlighting sections and reducing the volume for whole areas.