Musical Hallucinosis: Auditory Illusions After Hearing Loss and Cochlear Implantation

BackgroundPhantom auditory percepts are especially prevalent in healthy persons with hearing loss. No first-person description of the not uncommon illusion called musical hallucinosis (MH) has been published in relation to possible neural mechanisms for its occurrence.ObjectivesThe author presents his personal experience following implantation of a unilateral cochlear neuroprosthesis to try to compensate for progressive sensorineural hearing loss.ResultsThe MH included abrupt onset of persistent, robust singing of the Star-Spangled Banner, then other familiar songs and nursery rhymes by a men's choir without accompanying instrumentals, followed months later by continuous nonsense lyrics sung to a simpler stereotyped tune. The onset was associated with deafness as a complication of electrode placement within the cochlea, the early sizzling, synthetic, monotonal auditory sounds heard using the cochlear implant, and a burst of cacophonous tinnitus following a higher volume adjustment to the device.ConclusionsSeveral physiological alterations, including deafferentation-induced spontaneous auditory pathway activity that triggers higher auditory cortical areas to place the ambiguous inputs within the individual's prior experience of sound patterns, may help explain the evolution of MH and its persistence as a type of maladaptive neuroplasticity.