Same here. Reminds me of glitches typical of apps using a too small mixing buffer (in an attempt to run with a low latency?)
Runs smooth here on 8GB ram and a generic video card, playing a video on MPV at the same time, Ubuntu 15.10 Wily ...
Audio very badly stutters here under Firefox on a reasonable spec Win 8.1 PC - 3.6GHz i3-4160 dual core, GTX 970, 16GB RAM. Not an award winning spec system, but for single threaded maximised games (most) it's more than decent. ;)
Sound stutters on my PC which is pretty respectable. 16GB ram, Geforce 780 TI, i7-4790 3.6 GHz, Ubuntu.