I have been flying part 135 and part 121 since 1998...I have had a 1st class medical since 1997 and second class since 1988 and have never had to use headphones for a hearing test.
You will have to list medical conditions and a hearing loss is a medical condition.
Google flying and hearing loss. There are websites where you can ask an AME a question...I did before I had a hip replacement and got a lot of answers.
good luck!