Does the sound come from your speakers or the computer case? If it Bleeps is it a long bleep or short? How many bleeps? How long since you start your computer does the bleeping occur?
The beep could either be the Charging port is loose and your laptop is flicking between 'charging' and 'not charging'
Or it might be that the seeking arm on the hard drive is starting to wear out. It makes a kind of fast squeak, quite similar to a beep. In the shop, we've seen far too many new Dells with hardware issues.