ChromeOS Version 65.0.3322.0 (Official Build) canary (64-bit)
Firmware Version Google_Samus.6300.276.0

Steps to reproduce:

# Launch ChromeVox with ctrl + z
# Navigate to YouTube video that turns on captions by default. For the sake of this bug, you can just go to any video with captions and manually turn them on by navigating to the CC button and pressing the space bar. This is the video I used: https://www.youtube.com/watch?v=Zz3Ldnn3DAs
Expected: ChromeVox doesn't read captions or there's a way to disable it
Actual: ChromeVox reads captions, no way to disable except to hide the captions