7Otologic Causes of Tinnitus

FWhy the ear is the usual suspect

When a patient describes ringing, hissing or buzzing in the absence of any external sound, the ear is the first place to look — otologic disease is the most common category behind chronic subjective tinnitus [2013]. The reason is mechanistic: most of these patients carry some degree of hearing loss, frequently a high-frequency sensorineural loss that may be subtle or even subclinical on a standard audiogram [2013].

The unifying story is deafferentation. Damage to the cochlea — especially loss of outer hair cells — reduces the steady stream of afferent signals climbing the auditory nerve. The central auditory system, deprived of its expected input, compensates by turning up its own gain, and that maladaptive readjustment is heard as sound that is not there [2004]. So in otologic tinnitus the ear lights the fuse, but the brain rings the bell.

TNoise injury and presbycusis: the two commonest drivers

Noise-induced hearing loss and age-related hearing loss (presbycusis) are the two associations a clinician will meet most often. Both preferentially injure the high-frequency, basal end of the cochlea, which is why the accompanying tinnitus is usually high-pitched and the audiogram dips in the 3–6 kHz region [2004].

Loud sound damages more than hair cells. Even exposures that cause only a temporary threshold shift can permanently strip away the ribbon synapses between inner hair cells and auditory-nerve fibres — cochlear synaptopathy, or “hidden” hearing loss — which can generate tinnitus despite a normal pure-tone audiogram [2009]. This explains the young musician or soldier with bothersome ringing and a textbook-normal audiogram, and it is why hearing-conservation programmes matter in noise-exposed populations [2013].

TMénière’s disease: the low-pitched roar

Ménière’s disease stands out among otologic causes because its tinnitus is characteristically low-pitched — a roaring or buzzing, usually unilateral, that tracks the side of disease. It travels with the rest of the Ménière’s tetrad: episodic spontaneous vertigo, fluctuating low-frequency sensorineural hearing loss, and aural fullness [2015].

The pathological substrate is endolymphatic hydrops — distension of the endolymphatic compartment — which disturbs hair-cell function and neural encoding low in the cochlea [2020]. Clinically useful point: the tinnitus and fullness often crescendo just before a vertigo attack and may outlast it, so a fluctuating low-pitched roar with pressure should prompt you to ask specifically about spinning episodes [2015].

COtosclerosis and the conductive ear

Not all otologic tinnitus is sensorineural. Otosclerosis — abnormal remodelling of the otic-capsule bone that fixes the stapes footplate — classically produces a conductive hearing loss with associated tinnitus, and surgical correction of the conductive component (stapedectomy) frequently improves the tinnitus alongside the hearing [2025].

Chronic otitis media, ossicular discontinuity and tympanic-membrane perforation round out the conductive group: here tinnitus arises partly through inflammatory and mechanical disturbance of the middle ear and partly through the auditory deprivation that any conductive loss imposes. Reconstructing the sound-conducting mechanism often modifies the tinnitus, underlining that a careful otoscopic and tympanometric examination is mandatory before labelling tinnitus ‘idiopathic’ [2026].

CSudden sensorineural hearing loss: a time-critical cause

Idiopathic sudden sensorineural hearing loss (SSNHL) — a loss of ≥30 dB across at least three contiguous frequencies developing within 72 hours — very commonly announces itself with abrupt-onset unilateral tinnitus and aural fullness [2008]. The acute deafferentation is what makes the tinnitus appear so fast.

SSNHL is an otologic emergency: corticosteroids are most effective when started early, so a patient reporting sudden one-sided ringing with a drop in hearing needs urgent audiometry, not reassurance [2008]. And because a sudden unilateral loss can also be the herald of retrocochlear pathology, MRI is part of the work-up — a theme carried into the neurologic module [2014].