Final Cut Pro

For any audio work, you probably want to enlarge the height of your audio tracks first. You can do that by rotating the dial “Adjust Waveform”.

To adjust the over-all volume, select the clip(s) you wish to adjust with your mouse, or press “Select All” to select all clips on your timeline, and rotate the wheel/dial.

You can reset the value to 0db and remove possible keyframes by double tapping on the wheel action / dial.