The human body generates constant, low-level noises from biological processes, yet most people are unaware of them. The reason the heartbeat is not typically audible in the ears is due to sophisticated filtering mechanisms in the auditory system. While not hearing these internal sounds is normal, certain conditions can disrupt this natural silence, causing the perception of a rhythmic, heart-synchronized sound. Awareness of one’s pulse in the ear is a deviation from the norm that often warrants medical attention.
The Normal State: Why We Don’t Hear Body Sounds
The absence of constant, distracting internal noise results from the brain’s ability to filter and habituate to predictable sensory input. The auditory system is primarily designed to detect and process sounds originating from the external environment for communication and safety. To maintain this focus, the brain effectively tunes out the constant, low-frequency sounds created by internal functions like breathing, digestion, and circulation.
Physiologically, the body’s soft tissues and bone structure provide acoustic dampening that prevents internal sounds from directly stimulating the inner ear. Blood flow in healthy vessels is non-turbulent and travels at a velocity that produces sound below the threshold of human hearing. This sound energy must travel through surrounding bone and tissue before reaching the cochlea. Furthermore, the inner ear is a fluid-filled chamber, and sound waves entering from air-filled spaces, like the middle ear, are naturally attenuated unless amplified.
The brain’s continuous adaptation mechanism quickly registers constant, non-threatening stimuli and relegates them to the subconscious. This auditory filtering ensures that the nervous system is not overwhelmed by the body’s own predictable acoustic output. The lack of perceived internal noise is a sign of a healthy, functioning auditory and central nervous system.
Understanding Pulsatile Tinnitus
The sudden or persistent ability to hear one’s own heartbeat in the ear is a specific symptom known as pulsatile tinnitus. This condition is characterized by a rhythmic sound—often described as a whooshing, throbbing, or rushing—that perfectly matches the cardiac cycle. This is distinct from non-pulsatile tinnitus, which is typically a continuous ringing or buzzing sound that does not synchronize with the pulse.
Pulsatile tinnitus is generally caused by an abnormal sound source or an enhancement of sound conduction to the ear. The vast majority of tinnitus cases are non-pulsatile, often linked to noise-induced or age-related hearing loss. Pulsatile tinnitus is reported by a small minority of sufferers, representing approximately 4% of cases.
Pulsatile tinnitus can be categorized as either subjective or objective. Subjective tinnitus is heard only by the patient. Objective tinnitus is rare and can be audibly detected by a clinician using a stethoscope placed near the ear or neck. The presence of pulsatile tinnitus often suggests an underlying vascular or structural issue that requires thorough investigation.
Underlying Causes of Hearing Your Heartbeat
The causes of pulsatile tinnitus are grouped into conditions that either increase the volume of blood flow noise or enhance the transmission of that noise to the inner ear.
Vascular Causes (Turbulent Flow)
Vascular issues are the most common source, where turbulent blood flow creates audible noise. This turbulence often arises from the narrowing of an artery, such as atherosclerosis or carotid artery stenosis, which forces blood to rush through a restricted opening. Abnormal connections between arteries and veins, like arteriovenous malformations or fistulas, can also generate a loud, turbulent sound picked up by nearby auditory structures.
In the venous system, issues like transverse sinus stenosis, where a major vein in the brain is narrowed, can create a loud whooshing sound. This sound may sometimes be reduced by pressing on the jugular vein in the neck. These vascular causes account for a significant portion of identified cases.
Systemic Causes (High Flow States)
Systemic conditions that increase the speed or volume of blood flow, known as high cardiac output states, can also make the heartbeat audible. Examples include severe anemia, where the blood is thinner and flows faster, and hyperthyroidism, which increases heart rate and metabolic activity. Increased intracranial pressure, often referred to as idiopathic intracranial hypertension (IIH), is another frequent cause, particularly in younger, overweight females.
Conductive Causes (Enhanced Transmission)
Conductive issues enhance the transmission of internal sound through anatomical defects or masses near the ear. Bone abnormalities, such as superior semicircular canal dehiscence (SSCD), involve a thinning or opening in the bone covering part of the inner ear. This defect acts like a third window, allowing internal sounds, including pulse and eye movements, to be more effectively conducted to the cochlea. Additionally, vascular tumors in the middle ear, such as a glomus jugulare, can press against blood vessels or ear structures, leading to an audible pulse.
When to Consult a Healthcare Professional
Any instance of new or persistent pulsatile tinnitus warrants a medical evaluation to identify or rule out a treatable underlying cause. Because this symptom often points to vascular or structural issues, timely assessment is important, especially if the sound is unilateral or accompanied by other symptoms. An initial consultation should be with an otolaryngologist, a physician specializing in ear, nose, and throat conditions.
The diagnostic workup typically begins with a comprehensive hearing test, known as an audiogram, to assess hearing function. Based on the patient’s history and physical examination, imaging studies are often ordered to visualize the blood vessels and surrounding structures. Common non-invasive tests include Magnetic Resonance Angiography (MRA) and Computed Tomography Angiography (CTA), which provide detailed images of the arteries and veins in the head and neck.
Symptoms that require prompt attention include pulsatile tinnitus that is sudden in onset or accompanied by other signs:
- Sudden onset of the sound.
- Changes in vision.
- Unexplained headaches.
- Neurological symptoms like weakness or loss of sensation.
While many causes are benign, the symptom can be the first manifestation of a serious condition, such as a dural arteriovenous fistula or severe carotid stenosis. Identifying the source allows for targeted treatment, which can often resolve the pulsatile sound entirely.