Further Validation of Evoked Response Audiometry (ERA)

Abstract

For 162 pupils at Central Institute for the Deaf who had severe hearing impairment but whose thresholds lay within the limits of the audiometric equipment at 500, 1000, and 2000 Hz, comparisons were made between the “thresholds” estimated from the vertex (V) potentials, behavioral thresholds using the same audiometric equipment, and audiograms already on record. The data for 46 children four to 10 years old tested in 1965–66 did not differ significantly from results previously reported with older children. Average estimates of threshold were in excellent agreement: the difference of means for the groups, V potential vs. behavioral, was 0.1 dB; V potential vs. clinical audiogram, 2.2 dB. The average deviation of estimates for a single trial at one frequency, V potential vs. behavioral, was 7.9 dB. The children with impairments beyond the limits of the equipment were all identified as having very severe auditory impairment. The method of average evoked response appears to be completely feasible for passive audiometry of school children four years of age or more.