Suprasegmental characteristics of speech produced during simultaneous communication by inexperienced signers.

This study investigated suprasegmental variables of syllable stress and intonation contours in contextual speech produced during simultaneous communication (SC) by inexperienced signers. Ten hearing inexperienced sign language users were recorded under SC and speech-alone (SA) conditions speaking a set of sentences containing stressed versus unstressed versions of the same syllables and a set of sentences containing interrogative versus declarative versions of the same words. Results indicated longer sentence durations for SC than SA for all speech materials. Vowel duration and fundamental frequency differences between stressed and unstressed syllables as well as intonation contour differences between declarative and interrogative sentences were essentially the same in both SC and SA conditions. The conclusion that prosodic rules were not violated by inexperienced signers in SC is consistent with previous research indicating that temporal alterations produced during SC do not involve degradation of other temporal or spectral characteristics of English speech.

Perception of the voicing distinction in speech produced during simultaneous communication.

UNLABELLED: This study investigated the perception of voice onset time (VOT) in speech produced during simultaneous communication (SC). Four normally hearing, experienced sign language users were recorded under SC and speech alone (SA) conditions speaking stimulus words with voiced and voiceless initial consonants embedded in a sentence. Twelve hearing-impaired listeners participated, with three of them randomly assigned to audit the speech sample provided by each one of the four speakers under the SC and SA conditions. In addition, 24 normal hearing listeners were randomly assigned to audit the speech samples produced by the four speakers under the SC and SA conditions, three listeners in noise and three listeners in filtered listening conditions for each of the four speakers. Although results indicated longer sentence durations for SC than SA, results showed no difference in the perception of the voicing distinction for speech produced during SC versus speech produced during SA under either the noise or filtered listening condition, or any difference in perception for the hearing-impaired listeners. This conclusion is consistent with previous research indicating that temporal alterations produced by SC do not produce degradation of temporal or spectral cues in speech or disruption of the perception of specific English phoneme segments. LEARNING OUTCOMES: As a result of this activity, the participant will be able to: (1) describe simultaneous communication; (2) explain the role of simultaneous communication in communication with persons who are hearing-impaired; (3) discuss methods of measuring perception of voice onset time with hearing-impaired listeners and with hearing listeners under filtered and noise conditions; and (4) specify the ability of listeners to perceive the voicing distinction in speech produced during simultaneous communication.

Effect of syllable-initial voicing on vowel duration during simultaneous communication.

UNLABELLED: Vowel durations following the production of voiced and voiceless stop consonants produced during simultaneous communication (SC) were investigated by recording sign language users during SC and speech alone (SA). Under natural speaking conditions, or speaking alone (SA), vowels following voiced stop consonants are longer in duration than vowels following voiceless stops. Although the results indicated longer sentence durations for SC than SA, they showed no differences in the relative duration of vowels following voiced or voiceless stops. Vowel durations following voiced stop consonants were consistently longer than vowel durations following voiceless stops. This finding is consistent with previous research indicating that global temporal alterations in SC do not degrade temporal or spectral cues of spoken English. LEARNING OUTCOMES: As a result of this activity, the participant will be able to (1) describe simultaneous communication; (2) explain the role of simultaneous communication in communication with persons who are hearing-impaired; (3) describe how the voicing characteristic of syllable-initial consonants affects the duration of subsequent vowels; and (4) explain that simultaneous communication does not influence the relative durations of vowels following voiced and voiceless stop consonants.

Effects of noise and filtering on the intelligibility of speech produced during simultaneous communication.

UNLABELLED: This study investigated the effects of noise and filtering on the intelligibility of speech produced during simultaneous communication (SC). Four normal hearing, experienced sign language users were recorded under SC and speech alone (SA) conditions speaking Boothroyd's forced-choice phonetic contrast material designed for measurement of speech intelligibility. Twenty-four normal hearing listeners audited the speech samples produced by the four speakers under the SC and SA conditions, three listeners in noise and three listeners in filtered listening conditions for each of the four speakers. Although results indicated longer sentence durations for SC than SA, the data showed no difference in the intelligibility of speech produced during SC versus speech produced during SA under either the noise or filtered listening condition, nor any difference in pattern of phonetic contrast recognition errors between the SA and SC speech samples in either listening condition. This conclusion is consistent with previous research indicating that temporal alterations produced by SC do not produce degradation of temporal or spectral cues to speech intelligibility or disruption of the perception of specific English phoneme segments. LEARNING OUTCOMES: As a result of this activity, the participant will be able to (1) describe simultaneous communication; (2) explain the role of simultaneous communication in communication with children who are deaf; (3) discuss methods of measuring speech intelligibility under filtered and noise conditions; and (4) specify the ability of listeners to perceive speech produced during simultaneous communication under noise and filtered listening conditions.

The effects of simultaneous communication on production and perception of speech.

This article reviews experiments completed over the past decade at the National Technical Institute for the Deaf and the State University of New York at Geneseo concerning speech produced during simultaneous communication (SC) and synthesizes the empirical evidence concerning the acoustical and perceptual characteristics of speech in SC. Comparisons are drawn between SC and other modes of rate-altered speech that have been used successfully to enhance communication effectiveness. Of particular importance are conclusions regarding the appropriateness of speech produced during SC for communication between hearing and hearing-impaired speakers and listeners and the appropriateness of SC use by parents and teachers for speech development of children with hearing impairment. This program of systematic basic research adds value to the discussion about the use of SC by focusing on the specific implications of empirical results regarding speech production and perception.

Acoustic and perceptual characteristics of vowels produced during simultaneous communication.

UNLABELLED: This study investigated the acoustical and perceptual characteristics of vowels in speech produced during simultaneous communication (SC). Twelve normal hearing, experienced sign language users were recorded under SC and speech alone (SA) conditions speaking a set of sentences containing monosyllabic words designed for measurement of vowel duration, formant frequencies, and fundamental frequency in consonant-vowel-consonant (CVC) syllables and 60 listeners audited the speech samples. Although results indicated longer sentence and vowel durations for SC than SA, the data showed no difference in spectral characteristics of vowels produced during SC versus SA, indicating no degradation of vowel spectrum by rate alteration during SC. Further, no difference was found in listeners' ability to identify vowels produced during SC versus SA, indicating no degradation of vowel perceptual cues during SC. These conclusions are consistent with previous research indicating that temporal alterations produced by SC do not produce degradation of segmental acoustical characteristics of spoken English. LEARNING OUTCOMES: As a result of this activity, the participant will be able to (1) describe simultaneous communication; (2) explain the role of simultaneous communication in communication with children who are deaf; (3) describe vowel acoustics in English speech; (4) discuss methods of measuring vowel perception; (5) specify the acoustic characteristics of vowels produced during simultaneous communication; and (6) specify the ability of listeners to perceive vowels in speech produced during simultaneous communication.

Intelligibility of speech produced during simultaneous communication.

UNLABELLED: This study investigated the overall intelligibility of speech produced during simultaneous communication (SC). Four hearing, experienced sign language users were recorded under SC and speech alone (SA) conditions speaking Boothroyd's (1985) forced-choice phonetic contrast material designed for measurement of speech intelligibility. Twelve hearing-impaired listeners participated, with three of them randomly assigned to audit the speech sample provided by each one of the four speakers under the SC and SA conditions. Although results indicated longer sentence durations for SC than SA, results showed no difference in the overall intelligibility of speech produced during SC versus speech produced during SA, nor any difference in pattern of phonetic contrast recognition errors during SC. This conclusion is consistent with previous research indicating that temporal alterations produced by SC do not produce degradation of temporal or spectral cues in speech or disruption of the perception of specific English phoneme segments. LEARNING OUTCOMES: As a result of this activity, the participant will be able to (1) describe simultaneous communication; (2) explain the role of simultaneous communication in communication with children who are deaf; (3) discuss methods of measuring speech intelligibility; and (4) specify the ability of listeners to perceive speech produced during simultaneous communication.

Preservation of place and manner cues during simultaneous communication: a spectral moments perspective.

UNLABELLED: Spectral moments, which describe the distribution of frequencies in a spectrum, were used to investigate the preservation of acoustic cues to intelligibility of speech produced during simultaneous communication (SC) in relation to acoustic cues produced when speaking alone. The spectral moment data obtained from speech alone (SA) were comparable to those spectral moment data reported by Jongman, Wayland, and Wong (2000) and Nittrouer (1995). The spectral moments obtained from speech produced during SC were statistically indistinguishable from those obtained during SA, indicating no measurable degradation of obstruent spectral acoustic cues during SC. EDUCATIONAL OBJECTIVES: As a result of this activity, the participant will be able to (1) describe SC; (2) explain the role of SC in communication with children who are deaf; (3) describe the first, third, and fourth spectral moments of obstruent consonants; and (4) identify spectral moment patterns in speech produced during SC.

Preservation of second formant transitions during simultaneous communication: a locus equation perspective.

UNLABELLED: This study investigated the preservation of second formant transition acoustic cues to intelligibility in speech produced during simultaneous communication (SC) from a locus equation perspective. Twelve normal hearing, experienced sign language users were recorded under SC and speech alone (SA) conditions speaking a set of sentences containing monosyllabic words designed for measurement of second formant frequencies in consonant-vowel-consonant (CVC) syllables. Linear regression fits made to coordinates representing second formant transition onset and offset frequencies following stop consonant release of CVC syllables (locus equations) were used to examine place of articulation cues in both SA and SC conditions. Although results indicated longer sentence durations for SC than SA, locus equation slopes and intercepts obtained from speech produced during SC were virtually identical to those obtained during SA, indicating no degradation of stop consonant acoustic cues during SC. This conclusion is consistent with previous research indicating that temporal alterations produced by SC do not involve violations of other rules of spoken English. EDUCATIONAL OBJECTIVES: As a result of this activity, the participant will be able to (1) describe SC; (2) explain the role of SC in communication with children who are deaf; (3) describe second formant transitions in English speech; and (4) identify second formant transition patterns in speech produced during SC.