Dysacusis

Dysacusis is a perceptual disturbance of hearing in which sounds are heard with abnormal quality. It refers to distorted perception of auditory stimuli, including speech and environmental sounds, rather than simply a reduction in loudness. People with dysacusis may report that voices sound garbled, high-pitched, metallic, tinny, or otherwise unlike how they remember them, and that tones or musical sounds do not match their expected pitch or timbre. Dysacusis can occur with various forms of sensorineural hearing loss and may accompany other auditory disorders.

Causes and underlying mechanisms vary. It is often associated with cochlear pathology that disrupts frequency selectivity and neural coding, such as age-related (presbycusis), noise-induced, or ototoxic damage to hair cells. It can also arise from neural or central auditory processing disorders affecting sound discrimination and temporal processing. In some cases, dysacusis may be present even when pure-tone thresholds are only mildly reduced or within the normal range, reflecting subtle cochlear or neural dysfunction.

Diagnosis relies on clinical history and targeted audiologic testing. Standard pure-tone audiometry and speech discrimination tests assess overall hearing ability, while specialized tests for pitch discrimination, sound quality, and temporal processing can help characterize dysacusis. Additional evaluations, such as otoacoustic emissions, auditory brainstem responses, or imaging, may be used to identify the underlying pathology.

Management focuses on addressing the cause and mitigating perceptual distortion. Treatments may include hearing amplification with advanced signal processing to preserve or restore sound quality, counseling, and auditory rehabilitation. In selected cases, cochlear implantation or other interventions may be appropriate. The prognosis varies with etiology; some patients experience improvement with rehabilitation, while others continue to perceive distorted sounds despite therapy.