With iVolume you can bring all your iTunes songs to the same loudness. Therefore no simple peak analysis is made. Instead, the perceived loudness heard by human ears is calculated with an appropriate algorithm. The results of iVolume are much better than those of the built-in “Sound Check” function in iTunes.
iVolume does not change any data of your audio files, so there is no loss in quality. iVolume simply adjusts the “Volume Adjustment” slider that you can find in the information dialog of iTunes for every song.
What’s new in v1.2:
iPod workaround: Now iVolume can optionally adjust the songs so that they sound equally loud on the iPod. This was not the case because of an annoying bug in all current firmware versions of the iPod.
Optimizations: Improved memory management so that iVolume consumes less memory than before while operating long times.
License: Shareware $7
System Requirements: Mac OS X 10.2 or later, iTunes 4.0 or later.