Spectrotemporal Modulation Sensitivity as a Predictor of Speech-Reception Performance in Noise With Hearing Aids.
The audiogram predicts <30% of the variance in speech-reception thresholds (SRTs) for hearing-impaired (HI) listeners fitted with individualized frequency-dependent gain. The remaining variance could reflect suprathreshold distortion in the auditory pathways or nonauditory factors such as cognitive processing. The relationship between a measure of suprathreshold auditory function-spectrotemporal modulation (STM) sensitivity-and SRTs in noise was examined for 154 HI listeners fitted with individualized frequency-specific gain. SRTs were measured for 65-dB SPL sentences presented in speech-weighted noise or four-talker babble to an individually programmed master hearing aid, with the output of an ear-simulating coupler played through insert earphones. Modulation-depth detection thresholds were measured over headphones for STM (2cycles/octave density, 4-Hz rate) applied to an 85-dB SPL, 2-kHz lowpass-filtered pink-noise carrier. SRTs were correlated with both the high-frequency (2-6 kHz) pure-tone average (HFA; R2= .31) and STM sensitivity (R2= .28). Combined with the HFA, STM sensitivity significantly improved the SRT prediction (ΔR2= .13; total R2= .44). The remaining unaccounted variance might be attributable to variability in cognitive function and other dimensions of suprathreshold distortion. STM sensitivity was most critical in predicting SRTs for listeners < 65 years old or with HFA <53 dB HL. Results are discussed in the context of previous work suggesting that STM sensitivity for low rates and low-frequency carriers is impaired by a reduced ability to use temporal fine-structure information to detect dynamic spectra. STM detection is a fast test of suprathreshold auditory function for frequencies <2 kHz that complements the HFA to predict variability in hearing-aid outcomes for speech perception in noise.
National Military Audiology and Speech Pathology Center, Walter Reed National Military Medical Center, Bethesda, MD, USA joshua.g.bernstein.civ@mail.mil.
Joshua G W
JG
Bernstein
Linnaeus Centre HEAD Graduate School, The Swedish Institute for Disability Research, Linköping University, Sweden.
Henrik
H
Danielsson
Linnaeus Centre HEAD Graduate School, The Swedish Institute for Disability Research, Linköping University, Sweden.|Department of Clinical and Experimental Medicine, Linköping University, Sweden.
Mathias
M
Hällgren
Linnaeus Centre HEAD Graduate School, The Swedish Institute for Disability Research, Linköping University, Sweden.|Department of Clinical and Experimental Medicine, Linköping University, Sweden.
Stefan
S
Stenfelt
Linnaeus Centre HEAD Graduate School, The Swedish Institute for Disability Research, Linköping University, Sweden.
Jerker
J
Rönnberg
Linnaeus Centre HEAD Graduate School, The Swedish Institute for Disability Research, Linköping University, Sweden.|Eriksholm Research Centre, Oticon A/S, Snekkersten, Denmark.
Thomas
T
Lunner
D001309:Auditory Threshold; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural; D006801:Humans; D009622:Noise; D013060:Speech; D013067:Speech Perception
amplitude modulation; cognitive processing; hearing aids; noise; temporal fine structure