The bulk of QUnit tests have been fixed via T194620 / https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Wikispeech/+/428393 .
They pass on the CI job mwext-qunit-jessie which comes with Chromium 57. That job is legacy though and should be changed with a new one quibble-vendor-mysql-php70-docker. It runs the tests in a Docker container based on Debian Stretch and comes with Chromium 66. That eventually causes:
play() failed because the user didn't interact with the document first. https://goo.gl/xX8pDD
The linked documentation states Chrome has changed the autoplay policy in April 2018, I havent read the technical details though.
Once that case is fixed, I will migrate that repository so it no more use the old mwext-qunit-jessie Jenkins job but the new Quibble one based on Docker / chrome 66 .
Repro comment check experimental on a Wikispeech Gerrit change. Look at the job quibble-vendor-mysql-php70-docker