The sensation of hearing a rhythmic sound, often described as a clock ticking, a whooshing, or a steady beat within the ear or head, is a distinct and often unsettling experience. This internal perception of sound is sometimes confused with general tinnitus, which usually manifests as a continuous ringing or buzzing noise without a specific rhythm. The unique characteristic of this sound is its regularity, which suggests a physiological process is being amplified and perceived by the auditory system. This confirms that the ear is picking up vibrations or noises originating from inside the body.
Identifying the Sound: Pulsatile Tinnitus
The formal term for a rhythmic sound that is synchronized with the body’s circulation is pulsatile tinnitus. Unlike the more common forms of tinnitus, which are typically constant and high-pitched, this type involves a sound that pulses in time with the person’s heart rate. Synchronization can be confirmed by checking the wrist or neck pulse while listening to the sound; if they match, the sound is pulsatile. This strongly indicates the perceived noise is related to blood flow dynamics in vessels near the ear structure. Pulsatile tinnitus is relatively uncommon, accounting for less than 10% of all tinnitus cases. The sound is essentially the body’s circulatory system creating turbulent flow, which is then acoustically transmitted to the inner ear. When blood flows smoothly, it is generally silent, but when flow changes speed or encounters an obstruction, the resulting turbulence can become audible.
Vascular Explanations for Rhythmic Sounds
The majority of cases involving a pulse-synchronous sound are linked to changes in the vascular system, due to altered blood flow volume or structural issues in the vessels themselves. Conditions that increase the speed or volume of blood flow throughout the body can result in a generalized increase in the audible noise. For example, systemic conditions like anemia or hyperthyroidism can accelerate blood circulation, making the flow more forceful and easier to hear. Pregnancy can also lead to temporary changes in hemodynamics that cause this increased flow sensation.
Structural abnormalities in the blood vessels near the ear and brain are frequent causes of turbulent flow. Narrowing of an artery, such as carotid atherosclerosis, forces blood through a smaller opening, increasing its velocity and creating a loud, rushing sound. Similarly, conditions affecting the large veins that drain blood from the brain, like venous sinus stenosis, can cause a noisy disturbance in the blood return. This narrowing can create a whooshing sound that is often louder than arterial sounds.
High blood pressure (hypertension) forces blood against the vessel walls with greater pressure, which can make the blood flow more noticeable, especially in vessels close to the ear. Rare vascular malformations, such as arteriovenous malformations, create abnormal connections between arteries and veins. These tangled connections disrupt normal flow patterns, significantly increasing the turbulence and generating a loud, pulsating noise.
Non-Vascular and Muscular Origins
Not all rhythmic sounds perceived in the ear are tied to blood circulation; some originate from mechanical or muscular activity, often sounding more like a rapid clicking or ticking than a steady pulse. This mechanical form is described as objective tinnitus because the sound is sometimes loud enough for a doctor to hear it with a stethoscope.
A common cause is middle ear myoclonus, involving involuntary spasms of the tiny muscles within the middle ear, specifically the stapedius or tensor tympani muscles. Contraction produces a sound patients describe as rapid clicking or thumping, which is usually not synchronized with the heartbeat. The rhythmic nature of the muscle spasms can mimic the ticking of a clock.
Another non-vascular cause is a patulous Eustachian tube, where the tube connecting the middle ear to the back of the nose remains abnormally open. When the Eustachian tube is open, sounds from the nasal cavity and throat are transmitted to the middle ear. This can cause the person to hear the sound of their own breathing—a rhythmic, whooshing noise—or the crackling sound of the tube opening and closing.
When to Seek Medical Evaluation and Diagnosis
Hearing a persistent, rhythmic sound, particularly one synchronized with the heartbeat, warrants medical investigation due to the possibility of an underlying vascular condition. Pulsatile tinnitus can be a symptom of a serious issue affecting blood flow or pressure, such as a dural arteriovenous fistula or idiopathic intracranial hypertension. Consulting a specialist, such as an otolaryngologist or a neurologist, is the necessary first step to determine the source of the sound.
A thorough evaluation begins with the doctor taking a detailed history, including whether the sound can be stopped by gently pressing on the neck, a maneuver that suggests a venous cause. The doctor will use a stethoscope to listen to the neck and skull, attempting to hear the noise themselves, which confirms objective pulsatile tinnitus.
Diagnostic imaging plays a central role in identifying the root cause. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) are often the preferred tools to visualize blood vessels and surrounding structures. Blood tests may also be ordered to rule out systemic causes that affect overall blood flow, such as anemia or thyroid dysfunction. Finding and addressing the underlying cause is the most effective path toward resolution.