Normalize
This command normalizes the volume of the audio. It scans the selected audio for peaks and adjust the volume so that the peaks coincide with the target level specified in the options dialog box. The target level is shown in both decibels (dB) and percentage factor (%), with 0 dB being the maximum bandwidth of the file, and lower levels being negative decibel numbers.
Normalize each track independently: This option will treat each track separately when searching for and adjusting the peak levels. When multiple tracks are selected, this option will effectively bring each track to about the same volume relative to each other.
Normalize all tracks together: This option will treat all track as a unit when searching for and adjusting the peak levels. When multiple tracks are selected, only the highest peak level of all tracks is considered. Each track is adjusted by the same amount so that the volume of each track relative to each other will stay the same.