Duolingo audio not working in Safari

I used Duolingo successfully in Safari for years, but a few months ago the audio (native speakers saying the text) stopped. Everything else works normally, including all the Duolingo sound effects, but no speech audio.

I tried all the suggested fixes in other discussions here but none of them worked for me.

Since the problem persists, I just gave up on using Safari and use Duolingo with Firefox where it's fine.