Quality ratings for frequency-shaped peak-clipped speech: results for listeners with hearing loss.

Peak clipping is a common form of distortion in hearing aids and can reduce the subjective quality of the amplified speech. In a previous study involving listeners with normal hearing (Kates & Kozma-Spytek, 1994), the effect of peak clipping on speech quality ratings was studied using sentence test materials that were filtered using three different frequency response contours and then clipped at four different clipping levels. The present study extends the quality ratings to include those from a group of listeners having moderate to profound hearing impairments.

Acoustic-phonetic context considerations for speech recognition testing of hearing-impaired listeners.

Objective: To test for differences in the identification of consonants in carrier sentences versus in VCVs extracted from the sentences, as a function of listeners' hearing-loss categories: moderate, severe, profound. To examine whether pauses inserted in the sentences will facilitate identification of the consonants.

Design: Voiced stops and fricatives were identified by 11 listeners with moderate hearing losses and by 7 listeners with severe losses (between subjects design) for the conditions of consonants in sentences and in VCVs extracted from the sentences (repeated measures).

Temporal and spectral cue use for initial plosive voicing perception by hearing-impaired children and normal-hearing children and adults.

The influence of voice-onset time (VOT) and vowel-onset characteristics on the perception of the voicing contrast for initial plosive consonants was examined for hearing-impaired children, and normal-hearing children and adults. Listeners identified spoken 'DAD'--'TAD' stimuli controlled for VOT and vowel onset characteristics. Only six of 16 hearing-impaired children appropriately identified the exemplar DAD and TAD stimuli used as endpoints of VOT continua.

Phonetics of intervocalic consonant perception: retrospect and prospect.

This article reviews the production characteristics and perceptual cues of intervocalic consonants as a background for acoustic studies of consonant perception in fluent speech. Data show that in conversation intervocalic consonants occur much more commonly than consonants in initial or final position; all phonetic features are strongly represented. Production characteristics of intervocalic consonants are seen to depend on the tempo and rhythmic conditions of the syllables of which they are components.

Spectral cues to perception of /d, n, l/ by normal- and impaired-hearing listeners.

The alveolar consonants /d, n, l/ occur frequently in intervocalic position in conversational speech but have received little study for differences in their acoustic cues. Impaired- and normal-hearing listeners were investigated for use of consonant-segment versus transition-segment cues to recognition of /d, n, l/ in /aeCae/ tokens extracted from sentences. To examine the cues' contribution to /d, n, l/ recognition, the segments were degraded singly or in combinations in the tokens as follows: [aeC] or [Cae] transitions were replaced by adjacent pitch periods from the respective vowels; the consonant segments were replaced by silence or by a synthetic consonant approximating the summed low-frequency spectra of the /d, n, l/ murmurs.