A comparison of 40 Hz auditory steady-state response (ASSR) and cortical auditory evoked potential (CAEP) thresholds in awake adult subjects

Abstract

Evoked potential thresholds using the 40 Hz auditory steady-state response (ASSR) and cortical auditory evoked potential (CAEP) were recorded at 500 Hz and 4000 Hz test frequencies in 36 subjects with normal acuity, and 30 subjects with sensorineural hearing loss. ASSR threshold sensation levels (SLs) were lower in ears with greater degrees of hearing loss, and for the 500 Hz stimulus. Mean SLs (maximum duration of a single recording: 89 seconds) were as follows at 500 Hz and 4000 Hz respectively: normal hearing group, 16.9+/-10.3 dB and 42.4+/-14.4 dB; mild-moderate group, 10.6+/-8.8 dB and 23.8+/-8.1 dB; severe-profound group, 10.0+/-13.2 dB and 21.5+/-18.9 dB. CAEP SLs showed no change with hearing level and CAEP/behavioural differences were similar at each test frequency. Mean SLs for CAEP threshold (single recording duration: 84 seconds) at 500 Hz and 4000 Hz respectively were: normal hearing group, 10.3+/-6.4 dB and 11.5+/-3.8 dB; mild-moderate group, 8.4+/-7.4 dB and 13.2+/-12.4 dB; severe-profound group, 11.0+/-6.6 dB and 15.9+/-16.4 dB. The results of this study suggest that while both 40 Hz ASSR and CAEP can reflect the behavioural audiogram, CAEPs may provide a more reliable estimate of hearing in awake adults.

Hearing threshold estimation using concurrent measurement of distortion product otoacoustic emissions and auditory steady-state responses

“…In case of ASSR, the mean difference between ASSR thresholds and pure-tone thresholds amounted to 1.75 dB with a standard deviation of 9.66 dB. These findings agree well with those reported by Aoyagi et al (1993) and Tomlin et al (2006). Aoyagi et al (1993) reported a standard deviation of 40-Hz-ASSR threshold differences ranging between 6 and 8 dB across frequency with a correlation coefficient of 0.96.…”

The detection of adult cortical auditory evoked potentials (CAEPs) using an automated statistic and visual detection

“…It has been reported that a CAEP average consisting of 20-50 epochs, and replicated (Garinis & Cone-Wesson, 2007;Thornton, 2007;Tomlin et al, 2006), should provide an adequate SNR for visual response detection and that averaging an excessive number of epochs can be detrimental to response amplitude (Hyde, 1997;Walter, 1964). By contrast, other studies have suggested that extended averaging should not impair response amplitude (Lightfoot & Kennedy, 2006) as the greatest decrease in amplitude occurs from the fi rst to the second epoch after which amplitude stabilizes (Budd et al, 1998;Henry & Teas, 1968;Woods & Elmasian, 1986).…”

The effects of very slow rates of stimulus presentation on event-related potential estimates of hearing threshold

“…The N1-P2 is exceptionally sensitive to changes in stimulus intensity level, with its amplitude typically increasing in a linear manner with level (Adler & Adler, 1989;Picton et al, 1970Picton et al, , 1977. Because of this, the N1-P2 response has been suggested as an objective estimate of hearing threshold, with studies showing an accuracy of within 10 dB of behavioural values in most adult cases (Hone et al, 2003;Hyde et al, 1986;Lightfoot & Kennedy, 2006;Prasher et al, 1993;Rickards et al, 1996;Tomlin et al, 2006;Tsui et al, 2002;Yeung & Wong, 2007). Indeed, it has been called ''a measure of choice for most older children and adults'' when objectivity and good frequency specificity of the response is required (Stapells, 2002; for review see Hyde, 1997).…”