Since you haven't written here what your diagnoses with the only other dx that I wont mention where this might happens can help with being entertaining, distracting the negative and positive, it could be a hint for music, or just to enjoy life by playing video games or just being yourself...It is funny you typed this I had a guy take on the life of my T, and asked me why I did certain things like that, it wasn't anything overly just like a beat maker with my mouth nothing overly concerning....lol this is too funny, everything else I done in the my own company to entertain myself....I'm now remembering humming and eating could indicate something I don't know do your own research......