"لا أَعْرِف اِسْمها."
Translation:I do not know her name.
So why does it sound like "اِسمُها" while it is written as "اِسْمها"? Is there a grammatical relevance for the "u" or is it purely phonological?
Sorry, put on an answer first and realized I was mistaken with something.
The audio is correct. It is اسْمَها because the word اسم (name) is in accusative position, which requires (-a) on the last letter. Thus it is (Ismahá).
Apparently though they didn't type the FatHa on the (M) in the Arabic phrase above. The little circle on the (S) is Sukún, which notes that this letter is stable (i.e. not moved by any vowel).