This (text to speech) breaks pulse audio on my machine every time I enable reader view. Even if I'm not using text to speech or listening to anything else, I'll get a whiny noise until I restart pulse.
The browser does have this effect on Linux systems with pulseaudio. You will hear lots of static in your speakers, and after that the audio will be distorted until you restart pulseaudio.
What I cannot confirm is the relation of this to the speech-to-text engine. Reader mode most likely utilizes text to speech.
