At your age this will be news but what we do now when we get a test score we don't like is complain and the teacher changes it. It's called grade inflation. Harvey Mansfield gave up and gives all his student's two grades, the A they all expect and the F they usually actually deserve.
Even when complaining though there is usually this Kabuki dance where the student gives some story and the teacher pretends it is a reason. So what is your reason? Sort of guessing the missing piece of the puzzle is there are three more bursts you aren't hearing. If they are high in frequency and you are 81 then it's probably just normal high frequency hearing loss and nothing to worry about with the table. But that's just my guess. To get an A for effort let me know.
Even when complaining though there is usually this Kabuki dance where the student gives some story and the teacher pretends it is a reason. So what is your reason? Sort of guessing the missing piece of the puzzle is there are three more bursts you aren't hearing. If they are high in frequency and you are 81 then it's probably just normal high frequency hearing loss and nothing to worry about with the table. But that's just my guess. To get an A for effort let me know.