Greetings from a newbie!

I recently purchased Vegas Platinum 7.0. I was able to record the video, add titles and transitions with some minor hick-up. However, I'm having a hard time to mix sounds. The videw that I'm editing was shot at a restaurant and the event was a birthday party. I have 3 tracks; video, voice and music. Since the original sound track is mostly noise, I added the music, but I want to bring the original sound when singing the b-day song and cutting cake. I asked the Sony tech support, and I was told that I need to use envelope. I understand how to adjust the levels of voice and music, but how can I "cut" the track of voice and music so that I can adjust the levels where I want to adjust?

Thank you in advance.

You do not need to cut the track, as the support says use the rubber banding, press V on the audio track to bring it up then double click the line to make a point, do 4 of them and adjust up or down.

If you want to cut then split (press S) the audio track, separate the audio and video first otherwise the video will split as well. Adjust the audio by pulling the audio down, you can also drag the edges of the the adjoining audio to cross-fade (ease) the audio in to the newer lower.

Thank you for the reply. Actually, I don't have to cut the audio track. I guess I didn't use the correct terminology here. I'll try what you suggested. As long as I can adjust the audio levels of original track and music, that's all I need.

Thank you again. It works! I struggled a bit though. I didn't quite get "which line" I had to double click, it turned out that I had to click the center horizontal line within the track.