The results of cortical electric response audiometry in medico-legal investigations.
Cortical ERA was conducted in a consecutive series of 118 medicolegal cases (467 threshold determination in 209 ears). In organic cases, the distribution of subjective (manual pure tone audiometry)/objective (CERA) discrepancies was normal and centred on 0 dB, with only 3.2% of the discrepancies exceeding + 15 dB. Averaged over 3 or more test frequencies in one ear, only 4.4% of the discrepancies exceeded + 7.5 dB, as compared to 95.1% exceeding + 7.5 dB in those suspected of having a non-organic overlay. The pattern of non-organic overlay superimposed on noise-induced hearing loss is expected and demonstrated to produce a flattening of the dip in the audiogram. It is argued that such flattening is very rarely the end product of noise exposure.
D001299:Audiometry / Q000379:methods*; D001300:Audiometry, Evoked Response / Q000379:methods*; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D003937:Diagnosis, Differential; D005554:Forensic Medicine; D034381:Hearing Loss / Q000175:diagnosis*; D006315:Hearing Loss, Functional / Q000175:diagnosis*; D006317:Hearing Loss, Noise-Induced / Q000175:diagnosis*; D006801:Humans; D011930:Reaction Time