BT 750 freestyle phone keeps beeping?

Every 30 seconds my phone emits 2 'soft beeps'. At first I thought it was trivial but now, a full 3 days later, I might have started to loose my mind. I've tryed everything in the manual and reregistered and reset to factory defaults but the 'soft beeping' is relentless and it seems that I am destined to live in hell forever, a constant reminder that never again can I be fit in society and have a satisfactory level of functionality. I blame my loss of volition on that dam phone and it incessant infernal beeps.

any help would be a blessing, save me from the reign of terror.