Sorry about the delay, work made me forget about this. It's kind of like the site you linked to, but in the reverse. Volume goes up when it gets loud, which in turn makes it hard for people to understand what a person's saying, depending on the voice of the speaker.
We're only using Chromium with the mic, one machine uses Firefox or Chromium, depends on how much we're fighting with the worksite on just that one. They're work machines so nothing else save the games pack is installed. (And if something were to be installed we would actually be impressed about it.)