Audio laggs whenever my system is a little bit busy

For exampe, when I run: pacman -S some-exampe-package, my audio completely laggs. The sound quality sometimes goes down drastically and it the audio stutters like if it would take too long to load the next section of the audio file.
It happened while watching downloaded movies or playing music on spotify, I don't know if it only happens in those two cases.
Even when doing something simple, for example opening a web page makes the audio stutter for a few seconds.

EDIT: I always used bluetooth headphones when it happened.