Awareness ($5) is a new iPhone app that’s currently featured in the App Store and has been making the blogosphere rounds. The software works in conjunction with an iPhone’s mic and headphones to amplify any sounds in your environment that are louder than a specific threshold (which you set). Basically, background noise is ignored while anything unusual will be relayed:

Awareness! The Headphone App, allows you to listen to your music with complete peace of mind, knowing that important sounds (warnings, shouts, sirens, alarms or conversations) won’t be missed.

I’ve got a few co-workers who perpetually sport earbuds (“what did you say?”) that should probably expense Awareness. As for me, I’d prefer a true noise canceling app… freeing me to travel with one less accessory. Better yet, let’s see some of these features built directly into apps like Pandora and Slacker.