FF 60.0.1 Windows 7 x64 Drivers latest Sound Blaster ZX - optical connection DTS or DDL. This is what happens and it's happening on random: When I use keyboard arrows or just use mouse to move through Youtube streamline, sound suddenly sound distorted (like putting saw waveform over sound). It's not loud, just distorted. It happens at random time. Sometimes after ~10 minutes, sometimes after ~30 minutes. More-less. After that, every sound in Win becomes distorted in same way. The only way to regain normal sound is to reboot PC. It doesn't happen on any Video or Audio software doing same thing, just on Youtube currently. Didn't tested on other streaming websites (rarely using them). And I think that this started to happen on FF 59 or 60. Before that everythnig was OK.