How can I disable the "popping" sound when adjusting the volume?

[Alec Coulibaly]

This keeps happening on my Galaxy S4. I don't mind it when changing ringtone volume, but is the most annoying thing when changing volume while listening to music or watching a video. The worst part is that it seems to be random; most of the time it doesn't do the pop sound but sometimes when the phone restarts all of a sudden it's popping away like there's no tomorrow.