UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.102 Safari/537.36

Example URL:
https://jsfiddle.net/m5v89d9w/embedded/result/

Steps to reproduce the problem:
1. Open the JSFiddle web page
2. Speech synthesis begins
3. Close the window

What is the expected behavior?
The speech synthesis will stop playing after the window is closed.

What went wrong?
The speech synthesis continues playing, even after the tab or window containing the web page is closed.

Did this work before? N/A 

Is it a problem with Flash or HTML5? HTML5

Does this work in other browsers? Yes 

Chrome version: 50.0.2661.102  Channel: stable
OS Version: OS X 10.11.5
Flash Version: Shockwave Flash 21.0 r0

Further detaching the source of the audio from the web page, no audio indicator appears ( issue 335488 ).