It's not blood but the vibrations of the tensor tympani muscle. I learned to control it voluntarily and can make my ears rumble whenever I want. It's a pretty useless talent. Many people hear it when yawning.
There was an HN post a few weeks ago about Mercedes putting something in their car that activate the reflex just before an accident. To protect against hearing loss from the loud crash of an accident.
There was an HN post a few weeks ago about Mercedes putting something in their car that activate the reflex just before an accident. To protect against hearing loss from the loud crash of an accident.