Do you have a therapist? If so have the therapist write a very general note to the teacher explaing that this would make you uncomfterable, or maybe talk with the teachear about alternatives, I did this for a class, I am like you I can't put both earbuds in, or have my back turned. I had a class where we had an activity like you mentioned, and I went to my professer during office hours and told her I have PTSD adn doing this activty would aggrivate my symptoms, we agreed for me to do this at a diffrent time, where I could have one headphone over my ear and I was comfterable being in the room with the professer there. Maybe you and your teacher should brainstorm for ideas.

I wish you the best of luck and let us know how things go hun

Best wishes and peace
Sparrow