Chrome Version:	69.0.3494.0 (Official Build) dev (64-bit)
CrOS Firmware Version:	Google_Eve.9584.160.0

Steps to repro:
# Enable Dictation via Settings > Manage Accessibility Features
# Open the browser and navigate to https://www.onlinemictest.com/
# Start speaking into the mic test
# Put keyboard focus into the Omnibox (or another text field)
# Press ctrl + d to start dictating. 
Expected: unclear, perhaps if mic is in use, dictation doesn't start? Perhaps WAI? 
Actual: mic is being used by both applications at the same time 

I'm only really concerned in case this might be problematic on the back end, otherwise it is fine. I feel this is a borderline works as intended observation. I'll let the dev decide, please close as WontFix if it is WAI.