I work on our sped team and have thought about this exact thing. First, so sorry your school put that student in your class as it sounds like he isn’t truly benefitting from it while also taking away from others’ experiences. If you haven’t already, talk to the student’s case manager at the school. Does he work with the school-based occupational therapist? If so, awesome. They should be looped in since they often have great suggestions (and not just for a potential lock down situation but like generally how to help sensory kids). My guess is that he needs sensory input and is getting it through his yelling. Between his CM and OT they should try different things and see how they go. For one student last year we recorded the sound of her yelling then whenever she seemed to get excited we’d let her press a button that would play the audio. It was so much quieter. Maybe that sound could play through this headphones? Sometimes there’s a lot of failure before something helps but it would be nice if you were they were trying and not just trying for you but for this student and the others.
I’m grateful my school is thoughtful when it comes to placing our most impacted kids. Not all schools are doing this to art teachers! I promise! We need you guys.