Is Auditory Steady-State Response Testing the Key for Diagnosing Non-Organic Hearing Disorders? Implications for Current Audiological Practice.

Abstract

Background and ObjectivesTo describe all possible facets of non-organic hearing disorders (NOHD) and emphasize the superiority of auditory steady-state response (ASSR) over previously employed hearing assessment tools.Subjects and MethodsA series of seven patients consisting of three males and four females with NOHD were assessed at Attikon University Hospital (age range: 17-59 years). Three patients had Munchausen syndrome, three intentionally feigned hearing loss, and one intentionally feigned normal hearing. The audiological evaluation consisted of tympanometry, pure-tone audiometry, and ASSR testing.ResultsThe hearing of all patients was accurately determined using ASSR. The results were confirmed by auditory brainstem responses (ABR) and otoacoustic emissions.ConclusionsNOHD is a multi-faceted condition encompassing various etiologies. ASSR testing represents an objective and reliable method of hearing assessment, which can serve as a gold standard method for distinguishing NOHD from actual hearing loss. It can reliably indicate the hearing levels at the four main frequencies (500, 1,000, 2,000, and 4,000 Hz) by obtaining a valid estimated audiogram through statistical measures. Compared to ABR testing, ASSR thresholds are closer to the actual audiometric thresholds in the presence of hearing impairment and are superior when the corresponding pure-tone audiogram is widely ranging between the adjacent frequencies or when the obtained ABR curves are not easily distinguished. A non-confrontational approach should be adopted by ENT doctors towards cases of suspected NOHD as the use of ASSR could reliably assess hearing even when medical or medico-legal implications are involved.