The effect of background noise on subcortical neural encoding of speech in normal hearing individuals

Author/Creator

Author/Creator ORCID

Date

2015-08-10

Department

Towson University. Department of Audiology, Speech-Language Pathology and Deaf Studies

Program

Citation of Original Publication

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Copyright protected, all rights reserved.
There are no restrictions on access to this document. An internet release form signed by the author to display this document online is on file with Towson University Special Collections and Archives.

Subjects

Abstract

The purpose of the current research is to investigate the effects of background noise on subcortical neural encoding of speech in normal hearing individuals. It was proposed that increasing levels of background noise would degrade the Frequency Following Response (FFR). Six participants (age 23-24 years) participated in the current study. The Frequency Following Response was recorded on all six subjects in four different conditions: clean, 0 dB SNR, + 5 dB SNR, and -5 dB SNR. Grand average temporal waveforms were obtained across the 6 subjects for each listening condition. MATLAB software was used to analyze the temporal waveforms in the frequency domain. An FFT analysis was used to break down the response into the constituent frequencies. The magnitude of energy in the FFR spectrum at the fundamental frequency and first formant were measured in each test condition for each individual participant. Mean FFT values and standard deviation were also calculated. Results showed that the F0 magnitude and derived SNR for F1 decreased with increasing levels of background noise. Overall, it was concluded that the FFR was most degraded in the most severe background noise listening condition.