I've released TwitSonar that makes you feel in a submarine using sonar to catch tweets.

Imagine the soundless world.

You can hear nothing other than your sonar sound.

Reflecting the sound, you can hear tweets.

TwitSonar for iPhone, iPod touch, and iPad on the iTunes App Store

After launching, you can start with tapping screen.

Ping of sonar will be sent.

Nearby tweets will be displayed with reflecting sound.

You can specify keyword and ping region.