Neural representation of amplified speech sounds.
OBJECTIVE
To determine if (1) evoked potentials elicited by amplified speech sounds (/si/ and /[symbol: see text]/) can be recorded reliably in individuals, (2) amplification alters neural response patterns, and (3) different amplified speech sounds evoke different neural patterns.


METHODS
Cortical evoked potentials were recorded in sound field from seven normal-hearing young adults in response to naturally produced speech tokens /si/ and /[symbol: see text]/ from the Nonsense Syllable Test. With the use of a repeated-measures design, subjects were tested and then retested within an 8-day period in both aided and unaided conditions.


RESULTS
(1) Speech-evoked cortical potentials can be recorded reliably in individuals in both aided and unaided conditions. (2) Hearing aids that provide a mild high-frequency gain only subtly enhance peak amplitudes relative to unaided cortical recordings. (3) If the consonant-vowel boundary is preserved by the hearing aid, it can also be detected neurally, resulting in different neural response patterns for /si/ and /[symbol: see text]/.


CONCLUSIONS
Speech-evoked cortical potentials can be recorded reliably in individuals during hearing aid use. A better understanding of how amplification (and device settings) affects neural response patterns is still needed.
Tremblay
Kelly L
KL
Department of Speech and Hearing Sciences, University of Washington, Seattle, Washington 98105, USA. tremblay@u.washington.edu
Billings
Curtis J
CJ
Friesen
Lendra M
LM
Souza
Pamela E
PE
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D000704:Analysis of Variance; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006310:Hearing Aids; D034381:Hearing Loss / Q000503:physiopathology / Q000534:rehabilitation; D006801:Humans; D008297:Male; D009474:Neurons / Q000502:physiology*; D015203:Reproducibility of Results; D013018:Sound Spectrography; D013067:Speech Perception / Q000502:physiology*