Audio seems to degrade on Firefox. It works fine on other browsers I've tested (all of which being Chromium-based fwiw)
Firefox version: v133.0.3, though the same issue was seemingly reported for v132.0.2 a month ago #915
-Installed extensions: uBlock Origin (sorry), Google Translate, Dark Reader
Emu-JS version: v4.2, though I first found out about this due to a somewhat scummy website using v4.0.1.2
Hardware: a gaming laptop running windows 10, was far from being maxed out

Here's footage of Somari demonstrating the problem. Basically, the audio output initially starts out fine, but roughly 5 seconds in it'll slowly degrade into an irritating noise, with most mega drive games especially sounding horrible because of that. The type and severity can change sometimes when selecting UI options, minimizing the window, or leaving the tab inactive for a short while. Oddly, vsync doesn't seem to effect this issue.
SNES and MD also have some weirdness going off of the UIs built-in frame timer, sometimes it's at a proper frame rate, sometimes it says it's around 20 but the actual game is updating at rates that implies it's at 60, sometimes it caps at weird frame rates around 45 with the emulation speed reflecting that, it's a bloody wild west of inconsistency.