Yes, you can change the playback speed via the adjustment button. The adjustment button looks like two uneven dotted lines and is located in the top right-hand corner of your episode page. Please click the adjustment button, and scroll the playback speed bar to set the playback speed.

Alternatively, by clicking the cover photo area on the now playing page, the playback speed button will come out. You can tap the 1.0x to set the speed.