Is there a program that makes bunches of MP3's louder

[Dannyboyayyo]

I listen to books on the train and usually the sound is very very low so i use nero sound editor to make them louder however it does only one file at a time. i was wondering if there is a program that takes a folder of mp3's and does this.

 

[Webini]

http://mp3gain.sourceforge.net/index.php

 

[Dannyboyayyo]

Thank you so much for the quick reply and awesome program.