A rhythmic whooshing sound heard inside the ear, particularly when bending over, points toward an internal, physical source. This phenomenon is a form of tinnitus directly related to the circulatory system, meaning the sound is a physiological noise generated by blood flow near the auditory structures. The noise intensifying with a change in posture, such as leaning forward, provides a key clue about the underlying mechanism. This article explains the nature of this sound, why it is affected by body position, and the common conditions that may be its cause.
Understanding Pulsatile Tinnitus
The perception of a rhythmic sound in the ear synchronized with the heartbeat is known as pulsatile tinnitus (PT). Unlike the more common form of tinnitus, which is a constant ringing or buzzing, PT is a pulse-synchronous noise perceived as a throbbing, thumping, or whooshing sound. This noise is essentially the person hearing their own heartbeat or the turbulent movement of blood through nearby vessels.
PT is considered a form of objective tinnitus, meaning a clinician can sometimes hear the sound through a stethoscope placed near the ear or neck. The whooshing quality is caused by a change in blood flow dynamics in the large arteries and veins of the head and neck. When blood flow becomes turbulent, often due to an irregularity in a vessel, it creates vibrations transmitted to the nearby hearing structures.
The Connection Between Posture and Sound
The whooshing sound worsening when bending over indicates a vascular or pressure-related cause. Bending the head forward immediately alters the pressure dynamics within the head and neck, affecting blood flow through the large vessels. This action temporarily increases pressure in the venous system that drains blood from the head, including the jugular veins and dural sinuses.
When bending over, gravity assists arterial blood flow into the head but simultaneously impedes venous blood drainage back to the heart. This leads to a transient increase in venous pressure. This pressure change can cause a narrowed or irregular vessel to vibrate more intensely, amplifying the turbulent blood flow noise. The proximity of these vessels to the middle and inner ear structures allows the amplified sound to be detected.
If the pulsatile sound is caused by turbulent flow in the jugular vein, the change in position can compress the vein or alter flow velocity, making the sound more pronounced. Applying light pressure to the jugular vein in the neck may also reduce the sound, further confirming a venous origin.
Common Underlying Causes
The source of pulsatile tinnitus often involves localized issues affecting blood vessels near the ear, and these conditions range in severity.
Venous and Arterial Issues
One common vascular cause is a venous hum, which is turbulent blood flow in the jugular vein, often at a point where the vessel is narrowed or compressed. This increased turbulence creates a vibration easily picked up by the sensitive ear structures.
A more serious arterial cause relates to the carotid arteries in the neck, which supply blood to the head. Narrowing of these arteries, often due to atherosclerosis or plaque buildup, creates a constricted passage. This forces blood to flow at a higher velocity, generating significant turbulence that translates into the characteristic whooshing sound heard in the ear.
Intracranial Pressure
Another category involves issues of pressure within the skull, most notably Idiopathic Intracranial Hypertension (IIH). IIH is characterized by an increase in the pressure of the cerebrospinal fluid surrounding the brain. This can lead to the narrowing of the large venous sinuses that drain blood from the brain. This narrowing, or stenosis, creates a “whistle” effect, generating a loud, rhythmic sound often exacerbated by positional changes like bending over.
Structural Abnormalities
In rare instances, the sound can originate from highly vascular structures near the ear, such as glomus tumors. These benign tumors contain a dense network of blood vessels, and the high blood flow within the mass can generate the audible pulsing noise. Furthermore, abnormalities in the bone structure, such as a defect or thinning of the bone separating the ear from the blood vessels, can make normal blood flow sounds abnormally loud.
Diagnosis and Management
Because pulsatile tinnitus is frequently a symptom of an identifiable underlying medical condition, evaluation by a physician, often an otolaryngologist (ENT) or neurologist, is necessary. Diagnosis begins with a detailed history and physical examination, where the doctor listens to the neck and ear area with a stethoscope to determine if the sound is objective. This examination helps pinpoint the location of the turbulent flow.
Initial testing includes an audiological evaluation to assess hearing function, followed by specialized imaging to visualize blood vessels and surrounding structures. Common imaging studies include Magnetic Resonance Angiography (MRA) and Computed Tomography Angiography (CTA), which map the arteries, and Magnetic Resonance Venography (MRV), which focuses on the venous system. These tests are designed to identify structural abnormalities, such as vessel narrowing, aneurysms, or vascular malformations.
Management is directly tied to addressing the underlying cause. If the issue relates to high blood pressure or increased blood flow due to a systemic condition, medication may be used to regulate these factors. For conditions like IIH, treatment often involves medications to reduce intracranial pressure. In cases of severe venous stenosis or arterial anomalies, minimally invasive procedures like stenting or surgical intervention may be required to correct blood flow dynamics and resolve the symptom.