If you have a large collection of music on your iPod, chances are many of your songs have been recorded at varying volume levels. A very loud track that begins to play after your ears have adjusted to a lower volume can come as quite a surprise and cause temporary discomfort. However, your iPod has a sound check setting that normalizes all songs to an even volume so you can listen to your playlist peacefully. Writer Bio

How to Normalize the Volume on an iPod Playlist - 99