Strange issue, help needed.

every few minutes no matter what im doing on my computer, say im typing, it will appear as if i have alt tabbed and start making the microsoft "ding" type noise.

Example:

Playing wow just running straight ahead holding W, it will just start to constant make it like im not clicked into the game at the time.

Example B:

if im typing like i am here, it will suddenly just click off the browser and every letter i type after is not only not typed, but maked that same noise for every key i hit.

Anyone got any idea what the fuck might be going on? its a really annoying thing especially on wow.