UserAgent: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36

Example URL:

Steps to reproduce the problem:
1. Javascript code:

speechSynthesis.speak(new SpeechSynthesisUtterance('blah blah'))

What is the expected behavior?
If you mute tab and execute it no sound should be played

What went wrong?
Sound is played, but tab is muted.. I actually saw this in some advertisements. I muted tab and opened page and then I heared voice telling me to download some extensions, but page was muted. And I debugged it and I found that actually sound synthesis uterance is causing problem.

Is this a bug or I dont understand how chrome works?

Did this work before? N/A 

Is it a problem with Flash or HTML5? HTML5

Does this work in other browsers? Yes

Chrome version: 64.0.3282.167  Channel: stable
OS Version: 10
Flash Version: 1.4.8.1029

Contents of chrome://gpu: