Related Experiment Video
Updated: Jul 2, 2026
Electrically Evoked Stapedius Reflex Measurements in Cochlear Implantation and Its Application in the Postoperative Fitting Process
Published on: June 21, 2024
Effects of stimulus manipulation on electrophysiological responses of pediatric cochlear implant users. Part II: rate
Taryn Davids1, Jerome Valero, Blake C Papsin
1Department of Otolaryngology, Head and Neck Surgery, 6th Floor, Elm Wing, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8. taryndavids@hotmail.com
Insights
Stimulation rate impacts auditory brainstem responses in pediatric cochlear implant users. Matching electrical pulse rates does not improve prediction of behavioral thresholds, suggesting neural adaptation.
Area of Science:
- Neuroscience
- Audiology
- Biomedical Engineering
Background:
- Pediatric cochlear implant (CI) users often show discrepancies between electrophysiological and behavioral thresholds.
- This mismatch may stem from differing pulse presentation rates and durations between test types.
- Understanding these differences is crucial for optimizing CI programming and auditory rehabilitation.
Purpose of the Study:
- To investigate the effect of stimulus presentation rate on auditory brainstem and thalamo-cortical electrophysiological responses.
- To determine if synchronizing electrophysiological and behavioral testing rates enhances threshold prediction accuracy.
Main Methods:
- 14 pediatric CI users participated.
- Electrophysiological (auditory brainstem response - EABR, and early-middle latency response - EMLR) and behavioral thresholds were measured.
- Stimuli included single electrical pulses and pulse trains (2ms duration) at rates from 500 to 3600 pulses per second (pps).
Main Results:
- Low rates (500 pps) increased EABR wave eIII amplitude and decreased wave eV amplitude; higher rates reduced EABR amplitudes.
- EMLR amplitudes and EABR/EMLR latencies remained unaffected by increasing stimulation rates.
- Behavioral thresholds improved (decreased) with higher rates, but electrophysiological thresholds did not.
- Correlation between behavioral and electrophysiological thresholds did not improve when using matched stimulation rates.
Conclusions:
- Higher electrical stimulation rates may induce neural adaptation in the auditory brainstem of pediatric CI users.
- Synchronizing pulse presentation rates between electrophysiological and behavioral measures does not enhance the predictive accuracy of EABR and EMLR for behavioral thresholds.
Abstract:
Electrophysiological thresholds do not accurately predict behavioral thresholds in pediatric cochlear implant users possibly due to differences in rate and duration of pulse presentation. We asked: (1) Is there an effect of rate of stimulus presentation on the electrophysiological responses of the auditory brainstem and thalamo-cortex? and (2) can the relationship between electrophysiological and behavioral thresholds be improved by using the same rate of pulse presentation? Behavioral and electrophysiological (EABR and EMLR) responses were elicited for 14 children to single electrical pulses and pulse trains of 2ms ranging in rate from 500 to 3600 pulses per second (pps). Low rate (500pps) pulse trains resulted in an increase in EABR wave eIII amplitude and a decrease in wave eV amplitude. Further rate increases resulted in smaller EABR wave amplitudes. EMLR amplitudes were unaffected by increases in rate as were EABR and EMLR latencies. Behavioral thresholds decreased with increasing rate, however, there was no associated reduction in electrophysiological thresholds. Correlation between behavioral and electrophysiological thresholds did not improve by using the same rate of electrical pulse stimulation. Results suggest: (1) Higher rates of electrical pulse presentation increase the potential for neural adaptation in the auditory brainstem and (2) using the same rate of electrical pulse presentation does not improve the ability of EABR and EMLR thresholds to predict behavioral thresholds.