I think there has been a change in the Danish voices since the May update: I believe that the Danish voices are now the same as I hear on Duolingo, at least the male voice, which just as slow and annoying. They even make the same mistake: The audio pronounces “tv” as “til venstre” (to the left) not as “TV”. Exactly like on Duolingo!
I seem to miss the Danish voice I had before. I was practically in love with the girl 
The Danish voice shouldn’t have changed with the May update (and may indeed be the same as the voice used on Duolingo) - any chance you were using a voice local on your browser or device that might still be available in the game settings?
I think my problem might actually have been related to an upgrade from Android 9 to 10. After following a hint I got from @Tarob in my thread about Strange Finnish voices - #5 - Android Bugs - Clozemaster, it now works for me on Android.
On the web, using Chromium on Ubuntu 18.04, maybe there is not much I can do about it.
Most online services use one of two major text-to-speech services: Amazon Polly or Google Text to Speech (WaveNet) so it would not be surprising to hear the same voices on multiple services.