Steps to reproduce the problem:
1. Create a small app that makes uses of speech synthesis (TTS).
2. Enqueue several utterances. Start playing.
3. Let the device dims out the screen.

What is the expected behavior?
The speech continues even after the screen dimes out.

What went wrong?
When the screen dimes out and the current utterance ends, no new utterance is being spoken.

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 67.0.3396.87  Channel: stable
OS Version: 5.1.1
Flash Version: Shockwave Flash 28.0 r0

I'm developing a PWA that makes use of the TTS feature. The app is already installed (so, everything is in place: manifest, https, etc). Everything works perfect until the screen dimes out (on a mobile device - specifically several Samsung devices.. don't have any others at hand to check).

If speech is playing an utterance, after it ends playing it, even if there are others utterances enqueued, nothing happens. If I try to start a new utterance (with the screen dimmed out), nothing plays.

I understand that the above may/should happen on a website, but I don't get why this should happen on an installed app. Since I'm using the TTS to provide audible queues to people that are not actually looking at the screen, having them not working properly makes them not useful.