The audio is fine. Every word is spoken clearly and separately. It is just a question of practice. You learn your own language as a baby, it is harder for our adult brains to relax and make room for something that sounds 'strange'. But with time you will smile when you look back and think "How did I find that difficult?"
usually it would end in ים (if it is a musculine) and ות (if it is feminine), but unlike most languages in hebrew there is no "it" (for exemple room is musculine, floor is feminine, so חדר (room) in plural would be חדרים, and מרצפת (tile) would be מרצפות (though there is another translation to tile - אריח, and in this case the plural would be אריחים)). in cases of construct state, the musculine plural version would usually end wuth י (for exemple they are teenagers - הם בני עשרה) while the feminine would end with ות (they are teenagers - הן בנות עשרה)
It can mean you. It can mean at least two other things. When it's pronounced "at" then it's feminine singular "you". Here the word is pronounced "et" and is a definite direct object marker. It is not translated in this case, but serves to introduces the direct object, which is "the sandwiches" in this case.