"هَل أَنْتِ مُهَنْدِسة مَغْرِبِيّة يا سامْية؟"
Translation:Are you a Moroccan engineer, Samia?
The audio is correct up till "Samiyatan" ... this word is wrong and it should be "Sámiyah"
As a starter, the Nunation or Tanwin in Arabic is the indefinite marker (i.e. it is somehow equivalent to a/an in English to mark the indefinite noun).
Here, all the words (excluding Samiyah) are in nominative, so their ends should be (-u) but since they are indefinite noun/adjective compound, then they turned to (-un).
Similarly, if a word is in the accusative case (receiving the action from the verb) then it would get (-a) to its end, and if it is not defined with AL, then this changes to Tanwin (-an).
There are some rules and exception for specific words (specially feminine ones) which do not get Tanwin, but this is a bit too advanced for now.