Delivered by Ingenta to: University of Florida IP : 95.85.80.102 On: Tue, 20 Dec 2016 08:54:59 Cortical Auditory-Evoked Potentials in Response to Multitone Stimuli in Hearing-Impaired Adults DOI: 10.3766/jaaa.15068 Fabrice Bardy*† Jessica Sjahalam-King*† Bram Van Dun*† Harvey Dillon*† Abstract Purpose: To determine if one-octave multitone (MT) stimuli increase the amplitude of cortical auditory- evoked potentials (CAEPs) in individuals with a hearing loss when compared to standard pure-tone (PT) stimuli and narrow-band noise (NBN). Research Design: CAEPs were obtained from 16 hearing-impaired adults in response to PT and MT auditory stimuli centered around 0.5, 1, 2, and 4 kHz and NBN centered around 1 and 2 kHz. Hearing impairment ranged from a mild to a moderate hearing loss in both ears. Auditory stimuli were monaurally delivered through insert earphones at 10 and 20 dB above threshold. The root mean square amplitude of the CAEP and the detectability of the responses using Hotelling’s T 2 were calculated and analyzed. Results: CAEP amplitudes elicited with MT stimuli were on average 29% larger than PT stimuli for fre- quencies centered around 1, 2, and 4 kHz. No significant difference was found for responses to 0.5-kHz stimuli. Significantly higher objective detection scores were found for MT when compared to PT. For the 1- and 2-kHz stimuli, the CAEP amplitudes to NBN were not significantly different to those evoked by PT but a significant difference was found between MT stimuli and both NBN and PT. The mean detection sensitivity of MT for the four frequencies was 80% at 10 dB SL and 95% at 20 dB SL, and was comparable with detection sensitivities observed in normal-hearing participants. Conclusions: Using MT stimuli when testing CAEPs in adults with hearing impairment showed larger amplitudes and a higher objective detection sensitivity compared to using traditional PT stimuli for frequencies centered around 1, 2, and 4 kHz. These findings suggest that MT stimuli are a clinically useful tool to increase the efficiency of frequency-specific CAEP testing in adults with hearing impairment. Key Words: auditory-evoked potentials, diagnostic techniques, hearing science Abbreviations: ANOVA 5 analysis of variance; CAEP 5 cortical auditory-evoked potential; EEG 5 electroencephalography; HI 5 hearing impaired; MT 5 multitone; NBN 5 narrow-band noise; NH 5 normal hearing; PT 5 pure tone; RMS 5 root mean square; SD 5 standard deviation; SOA 5 stimulus onset asynchrony INTRODUCTION I n many clinical settings, cortical auditory-evoked potential (CAEP) testing is increasingly being used for hearing threshold estimation (Lightfoot and Kennedy, 2006; Van Dun et al, 2015) as well as hearing aid fitting evaluation (Van Dun et al, 2012). Often, CAEP testing is used in populations where accurate be- havioral responses cannot be elicited such as in infants, children, and populations with a disability, as well as cases of pseudohypacusis, as the test can be conducted on awake participants. Studies have shown that CAEPs *HEARing Co-operative Research Centre, Melbourne, Victoria, Australia; †National Acoustic Laboratories, Macquarie University, New South Wales, Australia Corresponding author: Fabrice Bardy, Australian Hearing Hub, Macquarie University, New South Wales 2109, Australia; E-mail: Fabrice.Bardy@- nal.gov.au This work was supported in part by the HEARing CRC, established and supported under the Australian Cooperative Research Centres Program, an Australian Government Initiative, and by support from the Australian Department of Health. The results presented in this article were presented orally at the International Evoked Response Audiometry Study Group in Busan, Korea, May 10–14, 2015. J Am Acad Audiol 27:406–415 (2016) 406