Pretty damn fast. I would guess 120 wpm is low.

Ever seen two deaf people get in an argument using sign language? It’s almost dizzying the speed at which they go.

I would guess that the limiting factor is the rate at which people understand what is being said, which would seem to be the same for spoken language as it is for sign language.

According to this, the average is 110–130 with top speeds at 150–160. Signers have an advantage in that several words are combined into one sign giving them an accelerated rate. According to this response, audiobooks have discovered that hearing people can only absorb up to 150–160 wpm so speaking any faster is a total waste of time & it’s much the same for those who are deaf!!!

.!#$^{&@! *}&%#!

Bruce Lee holds all records!

It seems that it would be easier to simultaneously listen to someone talking and translate into sign language than it would be to translate into another language. The sound of your own voice would interfere with what you are hearing the other person say. There are interpreters at the U.N. who regularly to this, but it must take a bit of training, even if the translator is fluent in both languages.