I get a buzzing/squealing noise in all speakers occasionally that's not effected by the volume at all but only seems to happen when other boats are around or I'm near a marina. Its also not effected by rpm's. The only way to stop it is by turning off the Touch or wait until it goes away. It didn't start until the third weekend I had the boat out and has done it ever since. Any ideas? Could a ground have come loose somewhere? Thanks.