First thing is to describe these noises a bit better .... do they sound like a second or so of music or sound you'd expect?
Do sounds and music play as normal otherwise?
What happens if you boot into Safe Mode? Do you still get those noises then?
What about if you boot into normal mode and disconnect the Internet (that rules out a background task trying to get something from online)?
Are the sounds even coming from the speakers? Or from the case itself?
If the speakers, then try unplugging the speakers from the jack and plugging them back in again first in case it's nothing more than a loose connection.
If you still get these sounds in safe mode or when disconnected from the Internet (and they're coming from your speakers), then this suggests a bad connection, a device driver fault for your sound card, or a bad sound card (although I'd say that would be quite rare).
Can you plug your speakers into something else to rule out the possibility that it's the speakers and not the computer itself?
Edit: Another thought, has the machine recently suffered a mechanical shock (for example, being put down heavily after moving it)? If so, it's possible that the sound card (and possibly other internal components) have become dislodged. The solution in that case would be to unplug the computer, ground yourself with a wrist-strap, open the case and make sure every component is firmly seated into the motherboard, along with all the cables.
Edited by Angoid, 06 June 2017 - 07:30 AM.