The following were tested, play sound fine now (or still work), and get media controls if the played sound is longer than the minimum threshold (8 seconds):
(Mostly aggregated from past p-b-i Bug reports about media controls)
* Amazon Music
* Spotify Website
* Google Translate: https://translate.google.com/#view=home&op=translate&sl=auto&tl=de&text=take%20measures%20to%20check%20the%20quality%2C%20performance%2C%20or%20reliability%20of%20(something)%2C%20especially%20before%20putting%20it%20into%20widespread%20use%20or%20practice.
* Cambridge dictionary: https://dictionary.cambridge.org/dictionary/english/example
* Forvo.com https://forvo.com/search/test/
* Cinemix radio stream https://www.radio.net/s/cinemix
* Player FM https://player.fm/series/der-nintendo-podcast
* This simple JS Fiddle done by Frederick Zhang in the bug report: https://jsfiddle.net/h78m6r0q/