iPod Shuffle 4th generation randomly stops and produces static noise

My 4th generation iPod Shuffle randomly stops playback and instead produces a constant hiss of static noise. When that happens, it doesn't react to any action. Unplugging and plugging the headphones doesn't do anything. The only way out is to turn it off and on. Then it might playback for a while until it does it again. This problem happens at totally random intervals, and it seems independent of the battery charge level. Anybody has any clue of what might be the cause of this strange behavior?