<b>Version: <Kenneth, what is the frequency?></b>
OS: Chrome

What steps will reproduce the problem?
(1)Navigate to Chrome://settings and then keyboard settings 
(2)Change the key mapping so that alt functions as ctrl and ctrl functions as alt
(3) Enable Chromevox by pressing ctrl alt z
4) Navigate around the page and attempt to temporarily silence the spoken feedback by pressing the alt key, which is now functioning as ctrl. 

What is the expected output?
Pressing that key will silence the feedback. 

What do you see instead?
Instead, nothing happens. Yet when I press the ctrl key which I have set to function as alt, THAT key silences speech. It seems that ChromeVox isn't honoring this change for this shortcut. 

That said, when I go to execute the alt shift L command or  alt shift s command for example, those are working fine with the new key mapping.