Do the blind hear better? Investigations on auditory processing in congenital or early acquired blindness. II. Central functions.
The same 18 normally hearing students and 18 matched normal-sighted students, as in part I of this study, were compared in regard to pure-tone integration, speech discrimination ability and late cortical-evoked potentials. The blind subjects showed increased disinhibition ('cleaning') with broad-band noise and a decreased inhibition with the same stimulus at the contralateral ear, better speech discrimination, especially with regard to sentence tests without and with competing environment-simulating noise, and, by electric response audiometry (ERA), a shortened N1 latency. Thus, the hypothesis of a better utilization of auditory information after the loss of the visual information channel could be confirmed, and may be ascribed to the plasticity of the central nervous system.
D000328:Adult; D001300:Audiometry, Evoked Response; D001301:Audiometry, Pure-Tone; D001306:Auditory Pathways / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D001766:Blindness / Q000151:congenital* / Q000209:etiology / Q000503:physiopathology; D004007:Dichotic Listening Tests; D006309:Hearing / Q000502:physiology*; D006801:Humans; D011930:Reaction Time; D013067:Speech Perception