The fast speaker is saying "mutachamisaten" and the slow speaker is saying "mutachamisatun". Throughout the course there have been extra sounds at the end of words and we are drawing to the end of the course and these have not been explained. I am sorry but I have not been able to figure this out inductively. When do you use what? What are their meanings? Are some masculine and others feminine? Are some singular and others plural? Or is this just padding, in which case Arabic is a very wasteful language.