Steady-state analysis of auditory evoked potentials over a wide range of stimulus repetition rates: Profile in children vs. adults

Abstract

Objective: Auditory steady-state responses (ASSR) evoked by recurrent brief tones were assessed over a wide range of stimulus repetition rates apropos the traditionally measured obligatory, transient, auditory evoked potentials. Repetition rates of ≤ 10 Hz have received little attention in the context of the ASSR stimulus-response analysis approach, speculated to provide technical advantages/additional information over more traditional transient stimulus-response paradigms. Design: Magnitudes were measured at repetition rates from 0.75 to 80 Hz, using trains of repeated tone-burst stimuli. Study sample: Twelve normal-hearing children and a reference sample of 25 young adults. Results: Results show that response magnitudes were significantly larger in children than adults at repetition rates of ≤ 5 Hz. Magnitudes were largest at the two lowest repetition rates, following the trends expected from the transient auditory evoked potential (AEP) literature. The harmonic sum is proposed as a more appropriate measure of response magnitude than amplitude of the fundamental alone. Conclusions: The analysis methods used in this paper may give information that will have applications for clinical testing. Of pragmatic importance is that the stimulus rate profile could be determined without subjective wave identification and/or interpretation, and thus by a method that is inherently more objective than conventional AEP analysis.

Key Words::

• Auditory evoked potentials
• auditory steady-state responses
• total harmonic distortion
• harmonic sum

Acknowledgements

Special thanks are given to Drs. Diane Sabo and Sheila Pratt for their input throughout this study, as well as Dr. Elaine Rubinstein for her assistance in statistical analysis. This project was supported in part by Intelligent Hearing Systems, Inc. and the School of Health & Rehabilitation Sciences Developmental Fund at the University of Pittsburgh. The methods reported herein include proprietary information (patent pending). The contents do not necessarily represent the views of the Department of Veterans Affairs or the United States Government.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.