Beeps coming fromNotebook sound card

I have a Thinkpad 390e with the ESS Solo Soundcard

There’s these strange beeps that come through the speakers and the headphone jack. It sounds like it’s from a drive spinning, but it is very consistant, regardless of drive activity, every 4-5 seconds you’ll hear three rapid beeps. The volume controller in windows doesn’t affect it, I can mute all and it’s still there. If anybody can help, I owe you my sanity.