A company called Soundhawk is about to release their product Scoop which is an earpiece that looks similar to a bluetooth headset, but far more powerful. The device is intended to augment your hearing and remove background noise from speech.
The web site engadget.com has a good review article of the product.
For those of you into retro TV series, you may remember The Bionic Woman (a spin-off series from The Six Million Dollar Man), who had a bionic ear to help her hear the quietest sounds.