Tinnitus is the perception of sound where no external source exists, often described as a phantom auditory sensation. While many people experience temporary episodes of ringing in the ears after loud noise exposure, for millions, this sensation is persistent and often debilitating. Tinnitus is not a single disease but rather a symptom that manifests in various ways and intensities. This article focuses specifically on the most common form, known as subjective tinnitus.
Defining Subjective Tinnitus
Subjective tinnitus refers to the perception of sound audible only to the person experiencing it. The sound originates from internal neurological activity and cannot be heard by a medical professional using external listening devices. This form accounts for nearly 99 percent of all tinnitus occurrences.
The sounds associated with subjective tinnitus are highly varied, often described as ringing, buzzing, hissing, whistling, clicking, or roaring. These phantom noises can be constant or intermittent, affecting one or both ears, or perceived as originating from within the head itself. The perception is thought to arise from abnormal neural activity within the auditory pathways, particularly the auditory cortex in the brain.
The rare alternative, objective tinnitus, is a physically measurable sound generated by physiological processes, such as turbulent blood flow or muscle spasms near the ear. Because it has a mechanical source, it can occasionally be heard by an examiner using a stethoscope. Subjective tinnitus is a neurological phenomenon, similar to phantom limb pain, where the brain generates a sensation in response to altered input.
Common Underlying Causes
Subjective tinnitus frequently develops in response to changes in the auditory system, often linked to a loss of input from the inner ear. When the brain receives less auditory information, it attempts to compensate by increasing the spontaneous activity of neurons in the central auditory pathway. This hyperactivity in the brain’s sound-processing centers creates the phantom perception.
The most frequent trigger is noise-induced hearing loss, which damages hair cells within the cochlea. Age-related hearing loss, known as presbycusis, is also a common cause, as it progressively reduces auditory input over time. Even modest loss of input is enough to initiate maladaptive changes in the central nervous system.
Certain medications are known to be ototoxic, meaning they can damage inner ear structures, leading to tinnitus. Drug classes implicated commonly include:
- Aminoglycoside antibiotics.
- High doses of non-steroidal anti-inflammatory drugs (NSAIDs) like aspirin or ibuprofen.
- Loop diuretics.
- Certain chemotherapy agents, such as cisplatin.
Tinnitus caused by ototoxicity sometimes resolves upon discontinuing the medication.
Other physical conditions can contribute by altering the input received by auditory pathways. Temporomandibular joint (TMJ) disorders, which affect the jaw joint, can influence neural signals leading to somatosensory tinnitus. Meniere’s disease, an inner ear disorder, also includes tinnitus as a prominent symptom alongside vertigo and fluctuating hearing loss.
The Diagnostic Process
Diagnosing subjective tinnitus involves identifying or ruling out any underlying medical conditions. The initial step is a detailed review of the patient’s medical history, focusing on noise exposure, medication use, and sound characteristics. A physical examination of the head and neck is also performed to check for objective causes, such as vascular issues.
The core of the diagnostic assessment is a comprehensive audiological evaluation, which includes pure-tone audiometry. This test measures the patient’s hearing sensitivity across various frequencies and volumes, often revealing hearing loss, a strong correlate of subjective tinnitus. The pattern of hearing loss can sometimes indicate the likely frequency or pitch of the phantom sound the patient is experiencing.
Specialized psychoacoustic tests are performed to quantify the patient’s subjective experience. These procedures include pitch and loudness matching, where the audiologist attempts to match an external sound to the specific sound the patient hears internally. These tests provide a baseline for characterizing the sensation and its intensity, which is useful for future management strategies.
Strategies for Managing Symptoms
Management focuses on reducing the distress and impact the phantom sound has on daily life. Sound therapy is a common and effective approach, aiming to reduce the contrast between the tinnitus and the environment. This involves using white noise machines, bedside sound generators, or environmental sounds to mask the internal noise, especially during sleep or quiet periods.
Habituation techniques are central to long-term management programs, such as Tinnitus Retraining Therapy (TRT). TRT combines directive counseling with low-level, continuous broadband noise delivered through specialized sound generators. The goal is to facilitate the brain’s ability to filter out the tinnitus signal and reduce the emotional reaction to the sound over time.
Cognitive Behavioral Therapy (CBT) is an effective psychological treatment for managing the emotional distress linked to persistent tinnitus. CBT does not eliminate the sound but helps individuals identify and reframe negative thought patterns and emotional responses. By teaching coping skills, CBT helps patients regain control and reduce the anxiety amplified by the constant noise.
Lifestyle adjustments mitigate factors that can worsen the perception of the sound. Reducing stress through relaxation techniques or biofeedback is helpful, as stress is known to exacerbate symptoms. Limiting the intake of stimulants like caffeine and alcohol is also recommended, as these substances can increase the sound’s perceived loudness or intensity.