The American Hearing Research Foundation explains that people hear a heartbeat in the ear due to muscular, vascular and tumor-related causes. This condition in which a person hears a sound resembling the heartbeat is known as pulsatile tinnitus.
Pulsatile tinnitus occurs when a blood vessel is close to the eardrum, according to the American Hearing Research Foundation. It also occurs when a vascular tumor, such as a glomus tumor, fills the middle ear or when a vein similar to a varicose vein makes enough noise to be heard in the ear.
The British Tinnitus Association explains that pulsatile tinnitus typically has the same rate as the heart, and it often occurs due to a change in blood flow in the vessels close to the ear or a change in awareness of that blood flow. These vessels include the large veins and arteries in the neck and the skull’s base. Smaller veins and arteries in the ear itself are also involved. Various factors, such as generalized increased blood flow, localized increased flow and turbulent blood flow, can alter the blood flow. When blood flows faster, it tends to create more noise than blood that flows slowly. The British Tinnitus Association notes that a person also tends to detect noise in the ear when blood flow is increased in a single blood vessel or group of blood vessels instead of a generalized increase.