High Pitched Beeping sound, Every 1-2 Seconds...........

[airems]

Started noticing it on and off for about a week now. I've tracked it down to the XM Satellite radio. Does it on all channels.
I've been know to be able to pick out an ant sneezing from miles away, or at least I think that!
Any input of similiar experiences would be helpful.

Thanks,

Jeff
2003 1500 with 1100 miles.