Critical bandwidth speech: Arrays of subcritical band speech maintain near-ceiling intelligibility at high amplitudes

Warren, Richard M.; Bashford, James A.; Lenz, Peter

doi:10.1121/1.4976031

Cited by 3 publications

(1 citation statement)

References 16 publications

(17 reference statements)

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“…However, unlike the others, this patient needed a small decrease in pitch (15 Hz) and needed the signal to be extremely muffled-as indicated by the low-pass filter at 300 Hz and maximum spectral smearing. These manipulations are consistent with the very poor speech understanding found for this patient (cf, Warren, Bashford, & Lenz, 2017). In addition, the patient needed (a) a sine vocoder signal to be added at a low level, which produced a ringing quality, and (b) a flanger.…”

Section: Resultssupporting

confidence: 81%

Looking for Mickey Mouse™ But Finding a Munchkin: The Perceptual Effects of Frequency Upshifts for Single-Sided Deaf, Cochlear Implant Patients

Dorman

Natale

Zeitler

et al. 2019

J Speech Lang Hear Res

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Purpose Our aim was to make audible for normal-hearing listeners the Mickey Mouse™ sound quality of cochlear implants (CIs) often found following device activation. Method The listeners were 3 single-sided deaf patients fit with a CI and who had 6 months or less of CI experience. Computed tomography imaging established the location of each electrode contact in the cochlea and allowed an estimate of the place frequency of the tissue nearest each electrode. For the most apical electrodes, this estimate ranged from 650 to 780 Hz. To determine CI sound quality, a clean signal (a sentence) was presented to the CI ear via a direct connect cable and candidate, and CI-like signals were presented to the ear with normal hearing via an insert receiver. The listeners rated the similarity of the candidate signals to the sound of the CI on a 1- to 10-point scale, with 10 being a complete match. Results To make the match to CI sound quality, all 3 patients need an upshift in formant frequencies (300–800 Hz) and a metallic sound quality. Two of the 3 patients also needed an upshift in voice pitch (10–80 Hz) and a muffling of sound quality. Similarity scores ranged from 8 to 9.7. Conclusion The formant frequency upshifts, fundamental frequency upshifts, and metallic sound quality experienced by the listeners can be linked to the relatively basal locations of the electrode contacts and short duration experience with their devices. The perceptual consequence was not the voice quality of Mickey Mouse™ but rather that of Munchkins in The Wizard of Oz for whom both formant frequencies and voice pitch were upshifted. Supplemental Material https://doi.org/10.23641/asha.9341651

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Section: Resultssupporting

confidence: 81%

Looking for Mickey Mouse™ But Finding a Munchkin: The Perceptual Effects of Frequency Upshifts for Single-Sided Deaf, Cochlear Implant Patients

Dorman

Natale

Zeitler

et al. 2019

J Speech Lang Hear Res

View full text Add to dashboard Cite

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Maintaining intelligibility at high intensities with arrays of subcritical width speech bands and interpolated noise

Bashford

Warren

Lenz

2017

The Journal of the Acoustical Society of America

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Speech intelligibility normally declines at high intensities, but this "rollover" effect decreases when steep filtering reduces sentences to an array of rectangular subcritical bands. The present study found that interpolating low intensity noise between the speech bands further decreases rollover, supporting the hypothesis that rollover is normally reduced by lateral inhibition of input from rate-saturated auditory nerve fibers. With noise also present within the speech (a 15 dB signal-to-noise ratio) an array of 6%-wide speech bands with interpolated noise was found to be 9% more intelligible at 100 dB than a spectrally continuous band of speech covering the same frequency range.

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Arrays of rectangular subcritical speech bands: Intelligibility improved by noise-vocoding and expanding to critical bandwidths

Warren

Bashford

Lenz

2018

The Journal of the Acoustical Society of America

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A previous study [Warren, Bashford, and Lenz (2017). J. Acoust. Soc. Am. 141, EL222-EL227] reported that arrays of subcritical width rectangular speech bands can produce near ceiling sentence intelligibility. The present study used noise-vocoded subcritical band speech arrays with analysis bandwidths of 4%, 2%, 1%, or 0.5% of center frequency. Intelligibility decreased when analysis and noise carrier bandwidths were matched. However, expanding carrier noise bandwidths to a critical bandwidth of 1/3-octave (26%) produced array intelligibilities either equaling or substantially exceeding that of the original speech band arrays. Implications concerning bandwidth requirements of envelope processing and the redundancy of envelope cues are discussed.

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Critical bandwidth speech: Arrays of subcritical band speech maintain near-ceiling intelligibility at high amplitudes

Cited by 3 publications

References 16 publications

Looking for Mickey Mouse™ But Finding a Munchkin: The Perceptual Effects of Frequency Upshifts for Single-Sided Deaf, Cochlear Implant Patients

Looking for Mickey Mouse™ But Finding a Munchkin: The Perceptual Effects of Frequency Upshifts for Single-Sided Deaf, Cochlear Implant Patients

Maintaining intelligibility at high intensities with arrays of subcritical width speech bands and interpolated noise

Arrays of rectangular subcritical speech bands: Intelligibility improved by noise-vocoding and expanding to critical bandwidths

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