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Updated: May 17, 2026

Measuring and Manipulating Functionally Specific Neural Pathways in the Human Motor System with Transcranial Magnetic Stimulation
Published on: February 23, 2020
Slow cortical potentials and amplification-part I: n1-p2 measures
Susan Marynewich1, Lorienne M Jenstad, David R Stapells
1School of Audiology and Speech Sciences, The University of British Columbia, 2177 Wesbrook Mall, Room 443, Vancouver, BC, Canada V6T 1Z3.
Slow cortical potentials (SCPs) in infants may not accurately reflect hearing aid amplification. Digital hearing aids showed smaller amplitudes and delayed latencies compared to analog, suggesting caution in clinical use.
Area of Science:
- Auditory Neuroscience
- Audiology
- Neurophysiology
Background:
- Slow cortical potentials (SCPs) are explored for infant hearing aid fitting.
- Existing literature presents conflicting evidence on SCPs' efficacy in this application.
Purpose of the Study:
- To investigate SCP amplitudes and latencies in normal-hearing infants under various hearing aid conditions.
- To evaluate the impact of analog and digital hearing aids with different gain settings on SCPs.
Main Methods:
- Utilized a 60ms, 1000Hz tonal stimulus at 30, 50, and 70 dB SPL.
- Compared SCPs in aided (Analog, DigitalA, DigitalB) and unaided conditions with 20 and 40 dB gain settings.
Main Results:
- Digital hearing aids yielded smaller SCP amplitudes than analog hearing aids.
- No hearing aid consistently increased SCP amplitude compared to unaided conditions.
- Analog hearing aids did not significantly alter SCP latency, while digital aids caused significant delays.
Conclusions:
- SCPs may not reliably indicate the amplified sound from hearing aids, especially digital ones.
- Interpreting "aided-SCP" results requires caution due to potential discrepancies.
- Further research is needed to determine the clinical utility of SCPs in hearing aid fitting.
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