TL;DR – Has anyone else noticed issues on spoken word podcasts at non-1.0x speeds? Is there some advanced setting to use high-quality audio sources during Playback Speed up/slow down? Else am I stuck choosing between 1.0x speed rich audio or low-fidelity playback on the Mac app?
I consume a ton of podcasts via the iOS app and was very excited to get a shared/synced experience via the new Catalina MacOS app. Keeping track of what's been played has been great and I was even more impressed to see native controls for Playback Speed as 1.5 or even 1.25 lets me get through so much more content.
In the iOS app, when I switch to the 1.5x speed (playing the same podcast, using the same headphones), the speech is faster, but still at the same fidelity as the 1.0x speed.
In the MacOS app, when I switch to either the 1.25x or 1.5x (or even 2.0) speed, there's a huge loss of audio fidelity that sounds like it's gone through extra compression, kind of tinny sounding. Based on using different bit-rate streams of audio content in the past, the sound quality change sounds like the speed change is being performed on a lower quality audio source rather than the full sound.
NOTE: I've only tested on my MacMini with the (latest as of this post) version of Catalina, but it has occurred on every podcast I've tried. FWIW, the playback via Safari and a YouTube publish of the same content at 1.5x speed does not exhibit the issue, so at least the computer can handle the faster audio.