Speakers stop working during braking

I've got an odd problem with my speakers. While driving with the gas pedal down they work just fine, but when I start braking the sound cuts out entirely. It stays this way until I start driving again, or as I found out recently I can slap the steering wheel while stopped and it will start back up again. Before poking around the electronics looking for the problem I figured I'd ask if anyone has had a similar problem and if you have any advice on fixing it? For the record it is a 2004 Aveo, the sound system is completely the stock one that came with the car.

Yes, the radio unit is going out most likely. The one in our 06 LT does the exact same thing, and bumpy roads will really aggravate it. However I have not done any work on it yet, still chasing codes lol We plan to swap it out with a new CD deck when I can make the time. You may need to pull the radio to troubleshoot what went wrong, or just install a new aftermarket unit.