Pulsatile tinnitus, a condition in which patients hear a heartbeat sound in one or both ears, is often due to vascular or muscular factors or tumors, explains the American Hearing Research Foundation. The sound sometimes occurs because of a blood vessel that is located near the eardrum or because the carotid artery is in an unusual location. A glomus tumor, a type of vascular tumor, that grows inside the middle ear can also cause patients to hear a pulse.
Enlargement of the jugular bulb is another potential cause of a heartbeat sound in the ear, notes the American Hearing Research Foundation. Additionally, high blood pressure, atherosclerosis, any type of tumor that places pressure on the head or neck, and arteriovenous malformation are other causes of pulsatile tinnitus, states Mayo Clinic.
Anything that raises blood pressure, such as stress or drinking coffee, can make the beating sound more detectable, according to Mayo Clinic. Atherosclerosis produces the pulsating sound by making blood vessels in the ear less flexible, resulting in a more forceful flow of blood through the area. Pulsatile tinnitus due to atherosclerosis tends to affect both ears, whereas the beating is usually limited to one ear in patients with arteriovenous malformation. In the case of arteriovenous malformation, a structural abnormality in the connections between the veins and arteries causes the beating noise.