Pixxo MP3 Player is noisy

Question

I have a 4Gb Pixxo MP3 player and during playback of the files there is a hum which is rather loud. As it changes tracts and the music stops the hum gets really loud, then there is a 'black' silence for a fraction of a second afterwhich the hum comes back and then the next tract plays. At low volume the hum is disturbing even when the tract is playing. Any ideas what it is or how to clean it up?