This post is from 2015:
We have talked so much about SLOW over the years, but I think we all still go too fast. We always go too fast. Our classes then split under this burden. What is too fast?
There are some posts from the recent years here that support 130 words per minute as minimal for our students. I think it should be well below 100 wpm for advanced classes and down around 20 or less for beginners.
Audiologist Ray Hull and has said this:
The auditory processing speed is the same in any language. For an adolescent, spoken speech at around 135 Words Per Minute is perfect for speech understanding, particularly when the student is learning a new language. So, 130 WPM may be even better. It will seem very slow to you, but the central auditory system of the student will appreciate it.