Cool app. I see it makes good use of the three band equalizer audio unit in iOS. This app would be great for hearing impaired.

Shameless plug: My start up also concerns audiology apps. Like the founder of SoundFocus, I've had hearing issues all my life- just had my second typmpanoplasty in November. Right now we have two apps that address tinnitus on iTunes. Check us out, www.bxtel.com