Blood pressure can be a cause, I'm sure. Also, I'm sure that extends to any pressure in your ear (say for instance, you constantly clench your jaw or grind your

Blood pressure can be a cause, I'm sure. Also, I'm sure that extends to any pressure in your ear (say for instance, you constantly clench your jaw or grind your teeth). I've heard ambient pink noise (not in headphones) helps, but anectdotally only.