Have a look at this guide:
http://kindlekitten.com/how-to/kindle-ba...
This happened to my sons kindle after 6 months of using it, we took it back to where we bought it and they said the speakers are buggered and there was nothing they could do. so I placed it on the counter, took my pants off, jumped on the counter and pumped out a crap the size of Oprah on the damaged kindle while my son stole another. Hope this helps!
This may sound like a joke but it's not. When I'm reading a book or playing a game a strange noise randomly appears that sounds like something is deflating . My first thought was that it was from an app in the background so I restarted the kindle but at random times I'd hear the noise. Anyone know where it's coming from because it appears even if i mute my kindle.