Tinnitus describes the perception of sound in the absence of any external noise. While most forms of tinnitus are heard only by the individual experiencing them, a rare type known as objective tinnitus produces sounds that a medical professional or another person can also detect. This article focuses specifically on objective tinnitus, exploring its unique characteristics, underlying causes, diagnostic approaches, and treatment strategies.
What Makes Objective Tinnitus Unique
Objective tinnitus stands apart because the sounds it generates are physically audible to an outside observer, often with the aid of a stethoscope placed near the ear or neck. This contrasts with subjective tinnitus, which is a “phantom” sound perceived only by the affected individual. Objective tinnitus is considerably less common, accounting for approximately 1% of all tinnitus cases.
The sounds associated with objective tinnitus are typically rhythmic and may synchronize with bodily functions like the pulse or respiration. People experiencing objective tinnitus often describe hearing whooshing, pulsing, clicking, humming, or even screeching sounds. A clinician’s ability to hear the sound is a defining feature, as it indicates a physical source that can be identified and treated.
Common Underlying Causes
Objective tinnitus arises from medical conditions or physiological issues, primarily involving vascular or muscular systems near the ear. Vascular conditions are a common cause, where changes in blood flow generate audible sounds. Examples include arterial bruits, which are turbulent sounds from blood flowing through narrowed or irregular arteries, or venous hums, caused by turbulent blood flow in veins like the internal jugular vein. Conditions such as atherosclerosis, arteriovenous malformations, or vascular tumors can also lead to pulsatile objective tinnitus. Increased blood flow due to strenuous exercise, pregnancy, anemia, or high blood pressure can also make vascular sounds more noticeable.
Muscular conditions can also produce objective tinnitus through involuntary contractions or spasms. Palatal myoclonus, characterized by rhythmic spasms of the soft palate muscles, can generate clicking or thumping sounds. Spasms of muscles within the middle ear, such as the tensor tympani or stapedius muscles, can result in clicking or buzzing noises. Temporomandibular joint (TMJ) dysfunction, involving issues with the jaw joint near the ear, can also lead to objective tinnitus. Inflammation or irritation in the TMJ region may affect nearby muscles and nerves, causing audible sounds.
How Objective Tinnitus is Diagnosed
Diagnosing objective tinnitus begins with a thorough medical history and physical examination. A key step involves a healthcare professional attempting to hear the sound, by placing a stethoscope over the patient’s ear, neck, or around the skull. The location and characteristics of the sound, such as its rhythm or quality, provide important clues about its origin.
Further diagnostic tests pinpoint the underlying cause. Imaging studies like magnetic resonance imaging (MRI) or computed tomography (CT) scans are used to visualize blood vessels, detect tumors, or identify structural abnormalities in the head and neck region. Angiography, which involves imaging blood vessels, may be performed to assess blood flow issues like arteriovenous malformations or stenoses. Audiological evaluations, including hearing tests, are also conducted to assess hearing function and rule out other ear-related issues. Blood tests might be ordered to check for systemic conditions such as anemia or thyroid problems that could contribute to objective tinnitus.
Management and Treatment Options
Treatment for objective tinnitus primarily focuses on addressing the underlying cause. For vascular conditions, medical management might involve medications to control blood pressure or address anemia. Surgical intervention may be necessary for vascular malformations, aneurysms, or tumors that are generating the sound. If the tinnitus is caused by muscle spasms, muscle relaxants or even botulinum toxin injections can be considered to alleviate the contractions.
For cases linked to temporomandibular joint dysfunction, treatment may involve physical therapy, dental interventions, or stress management techniques to reduce jaw clenching and grinding. If the underlying cause cannot be eliminated or the sound persists, general tinnitus management strategies may be employed to help individuals cope. These can include sound therapy, which uses external sounds to mask or distract from the tinnitus, or counseling approaches like cognitive behavioral therapy to help manage the perception and impact of the sound.