Why Use iPhone Sound Check Setting
A problem you are likely to face when listening to digital music on your iPhone is the variation in loudness between songs. Inconsistencies in volume levels between songs develop as you build your collection. Given that the contents of most digital music collections come from different sources, including digital music download stores and music CDs, you’ll eventually find yourself frequently adjusting the volume level. You don’t have to deal with this inconvenience on the iPhone. Instead, use the Sound Check option to play your songs at the same volume. With Sound Check, the iPhone measures the loudness of all the songs you synced to your iPhone and then computes a normalized playback volume level for each one. This modification in output volume isn’t permanent, so you can revert to the original volume levels at any time by turning off Sound Check.
How to Turn On Sound Check on iPhone
Sound Check is disabled by default, but you can turn it on if you know where to look. To configure Sound Check for the iPhone, follow these steps: