I think I would consider this to be self harm.
You are hurting yourself, and the reason is to self soothe by the sounds of it.
Sometimes we have to hurt ourselves, eg a diabetic injecting insulin, someone pulling out a splinter, leg waxing etc. but these things are done for a different purpose, and the pain and harm is a (usually unwanted) side effect.
So, if you're doing something and the reason is to feel pain, that's different.
Can you get some help with this? Maybe call a helpline or talk to someone you trust?