I have balance issues. I hear crisp metallic sound when I roll my head in a circular motion. It seems to be caused by the friction of neck bones. I perhaps have pulsatile tinnitus. I wonder if someone can tell what causes pulsatile tinnitus. It does not seem to happen when my eyes move back and forth.
The most common reason would be middle ears plugged with fluid, or abnormally functioning eustachian tubes.
Are you having any dizziness? Can you hear other body sounds; for instance, when you move your eyes back and forth? If that also makes a sound, you may need to be evaluated for SCD.