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Design and implementation of frequency-following response recording system

Abstract Objective: The frequency-following response (FFR) is the compound phase-locked brainstem response to periodic components of sound stimuli, and is closely related to pitch perception. Its weak amplitude often prevents its measurement with a high signal-to-noise ratio (SNR). Recording of FFR using multichannel EEG is possible but expensive and it involves the manual screening of raw data. Design: We describe a new method to extract FFR features by prescreening the raw data using automatic monitoring of sound pressure in the ear canal. Removal of stimulus artifacts, noise reduction, and data selection were systematically studied. Study sample: The reliability of our new method was tested by comparing FFRs tracking accuracy and pitch perception in fifteen individuals with normal hearing. Results: The extracted FFRs tracking accuracy was significantly correlated with behavioral measures of pitch perception, indicating that FFR could be used to represent individual differences in pitch perception ability among a population with similar hearing characteristics. Conclusion: The designed system could extract FFR signals more accurately with high SNR after signal prescreen and noise reduction.