128 or 192 quality

The pro tier says around 10 hours of audio export. Is this at 128kbps or 192?

Ultimately I'm wondering whether it's better to pay the 20% more for 192 or stick with 128.

Ive read that anything up from 64kpbs won't make much difference just for speech.

I know pcm is available via api, shame they couldn't offer that from the website. Seems backward offering old fashioned Mp3 export.