Tinnitus is the perception of sound when no external source is present. This phantom noise is a common symptom, affecting 10% to 25% of adults. Tinnitus is not a disease itself but a symptom of an underlying issue within the auditory pathway. Understanding the testing process helps determine if this condition is present.
Recognizing Tinnitus: Symptoms and Self-Observation
The experience of tinnitus is highly individual, but it typically involves perceiving sounds such as ringing, buzzing, hissing, roaring, clicking, or humming. The sound may be continuous or intermittent and can occur in one ear, both ears, or seem to originate from inside the head. The pitch can range from a low roar to a high-pitched squeal, and the loudness can vary significantly.
Most cases, over 99%, are classified as subjective tinnitus, meaning only the individual can hear the sound. This type is commonly associated with auditory system changes, often linked to hearing loss. Conversely, objective tinnitus is rare and can sometimes be heard by an external examiner, usually with a stethoscope.
Objective tinnitus often has a clear physical source, such as blood flow or muscle spasms near the ear. It may be described as a rhythmic pulsing or whooshing sound synchronized with the heartbeat. Self-observation involves noting the sound’s specific characteristics, including when it started and any changes in intensity or frequency. Monitoring whether the sound affects one or both ears provides initial clues for professionals.
The Professional Tinnitus Evaluation
A formal diagnosis begins with a comprehensive hearing assessment, typically performed by an audiologist or an otolaryngologist (ENT specialist). This evaluation uses standardized hearing tests and specialized tinnitus measures. The initial step is pure-tone audiometry, performed in a sound-isolation booth to measure hearing thresholds across frequencies. The results determine if hearing loss is present, which is the most common condition associated with subjective tinnitus.
Tympanometry is an objective test that measures the movement and function of the eardrum and middle ear. This assessment helps rule out middle ear issues, such as fluid or eustachian tube dysfunction, which can contribute to the sounds. Speech discrimination tests are also administered to determine how clearly the patient can hear and understand spoken words at different volumes.
Psychoacoustic measures, like pitch and loudness matching, are specific to the tinnitus sound itself. During pitch matching, the patient identifies the external tone that most closely matches the frequency of their tinnitus. Loudness matching determines the minimum intensity of an external sound required to equal the perceived loudness. These tests are not used for diagnosis, but they provide a quantifiable baseline helpful for subsequent management and treatment planning.
Identifying Underlying Medical Triggers
Since tinnitus is often a symptom, the diagnostic process extends beyond audiological testing to investigate underlying medical triggers. The initial consultation includes a targeted history and a physical examination of the head, neck, and ears. During this exam, a physician may palpate the temporomandibular joint (TMJ) and neck muscles, as dysfunction in these areas can be linked to somatic tinnitus.
If objective tinnitus is suspected (rhythmic or pulsatile), a physician will look for vascular causes. Changes in blood flow near the ear, possibly due to high blood pressure or atherosclerosis, can create a sound audible to the examiner. If medical conditions are suspected, blood tests may be ordered to check for issues like thyroid disorders, anemia, or other chronic conditions linked to tinnitus.
Imaging studies, such as magnetic resonance imaging (MRI) or computed tomography (CT) scans, are typically reserved for specific presentations. They are most often recommended for patients experiencing unilateral tinnitus or pulsatile tinnitus, where a structural issue is more likely. Imaging can help rule out rare but serious causes, such as a vestibular schwannoma (acoustic neuroma) or vascular anomalies near the inner ear.