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Biomedical subjects

R L Whitehead

Publications and source records attributed to R L Whitehead.

31 records · Page 2Linked to original sources

Spectrographic and perceptual features of vocal tension/harshness in hearing-impaired adults.

Twenty hearing-impaired adult males exhibiting a range of severity of vocal tension/harshness sustained the vowels /a/ and /u/, at a constant intensity level and read the first two sentences of the Rainbow Passage. Recordings of the vowels and sentences were rated for degree of severity of vocal tension/harshness on a 5-point, equal-appearing-interval scale by three speech pathologists. Each vowel production was analyzed to produce a narrow-hand (10 Hz) frequency-by-amplitude acoustic spectrum in which the levels of inharmonic energy, i.e., noise components, were measured in dB SPL over the frequency range 100--3000 Hz. Significant correlations were obtained between: mean ratings of vocal tension for sentences and for vowels; mean ratings of vocal tension for vowels and average spectral noise levels for vowels; and mean ratings of vocal tension for sentences and average spectral noise levels for vowels.

Acoustics↗

Description and evaluation of structured speaking and listening activities for hearing-impaired adults.

This study was designed to evaluate improvement in word comprehension, pronunciation, and auditory discrimination as a result of structured group experience in speaking and listening. Subjects included 75 college students with hearing impairment and auditory discrimination for speech. Subjects were divided into three groups matched on the basis of hearing characteristics. Groups A and B received 20 hours of instruction over a 10-wk interval. Group A was evaluated relative to word comprehension, word usage in writing, and pronunciation. Group B was evaluated relative to auditory discrimination before and after training. Group C (control) did not receive training but auditory discrimination was evaluated over the 10-wk interval. Significant improvements in word comprehension, word usage in writing, pronunciation, and in auditory discrimination were achieved as a result of training. No significant change in auditory discrimination was observed in the control group.

Adult↗

Harmonic levels and vowel roughness.

In this study the effects of vowel roughness on the level of harmonics in test vowel spectra were investigated. Twenty normal-speaking adult males sustained productions of each of the vowels (formula: see text) first normally and then with simulated abnormal vocal roughness, at one intensity. A tape recording of each production was rated for roughness on an equal-appearing intervals scale by 11 judges and was also analyzed to obtain its 3-Hz bandwidth amplitude-by-frequency acoustic spectrum. The median roughness rating, the level of the first five spectral harmonics, and the f0 of each production were obtained. It was found that the level of the first three harmonics for each test vowel diminished with an increase in roughness (as was hypothesized from earlier results), but the higher harmonics of /u/ and /i/ showed some reversals. A moderately large negative correlative relationship was shown between lower-harmonic levels and median vowel roughness. A possible explanation of the higher-harmonic reversals was offered. The results suggest that spectral noise level measurements may provide a more reliable acoustic index of vowel wave aperiodicity and vowel roughness than measurements of harmonic level.

Adult↗

Stimulus picture identification in articulation testing.

The present study was designed to compare the percent of correct initial identification of stimulus pictures on the Goldman-Fristoe Test of Articulation with the percent correct identification on the Arizona Articulation Proficiency Scale. This study was undertaken in an effort to clarify the results of a previous study in which the Goldman-Fristoe, a test designed to reduce time of administration, took significantly longer administration time than the Arizona, a traditional type of articulation test. Twenty normal-speaking and 20 articulation-defective children served as subjects for the study. Each subject was administered those portions of the articulation tests which included stimulus pictures used to elicit production of the consonants and consonant blends. Each child's initial identification of the stimulus picture was recorded. Results indicated that the Arizona test elicits significantly (p less than 0.001) more correct initial stimulus picture identifications thandoes the Goldman-Fristoe test.

Child↗

Sentence intonation and syllable stress in speech produced during simultaneous communication.

This study investigated prosodic variables of syllable stress and intonation contours in contextual speech produced during simultaneous communication (SC). Ten normal-hearing, experienced sign language users were recorded under SC and speech only (SO) 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 SO 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 SO conditions. The conclusion that prosodic rules were not violated in SC is consistent with previous research indicating that temporal alterations produced by simultaneous communication do not involve violations of other temporal rules of English speech.

Communication↗

Effect of sign task on speech timing in simultaneous communication.

The purpose of this investigation was to study the effect of the signing task on temporal features of speech during simultaneous communication (SC). The effects of three independent variables: (a) communication mode (speech only vs. SC); (b) sign task demand (base vs. elaborated signs); and (c) type of sign movement (kinetic vs. morphokinetic) were studied on five dependent variables: (a) word duration; (b) sentence duration; (c) diphthong duration; (d) interword interval before signed experimental word (IWIB); and (e) interword interval after signed experimental word (IWIA). Audio recordings were made of 12 normal hearing, experienced sign language users speaking experimental words that varied in sign task demand and movement under SC and speech only (SO) conditions. Results indicated longer sentence durations for SC than SO and longer anticipatory durations of IWIB and diphthong before signed words, especially those using signs with greater task demand or with movements including hand shape change. IWIA only lengthened for SC vs. SO with no further effect of sign task demand or movement. These results indicate finite effects of sign task demand and movement on pause and segment durations before the sign but not as strong an effect as has been reported for increased finger spelling task length.

Communication↗

Production and perception of final consonant voicing in speech during simultaneous communication.

Simultaneous communication combines both spoken and manual modes to produce each word of an utterance. This study investigated the potential influence of alterations in the temporal structure of speech produced during simultaneous communication on the perception of final consonant voicing. Experienced signers recorded words that differed only in the voicing characteristic of the final consonant under two conditions: (a) speech alone and (b) simultaneous communication. The words were digitally edited to remove the final consonant and played to 20 listeners who, in a forced-choice paradigm, circled the word they thought they heard. Results indicated that accurate perception of final consonant voicing was not impaired by changes in the temporal structure of speech that accompany simultaneous communication.

Communication↗

Production and perception of final consonant voicing in speech produced by inexperienced signers during simultaneous communication.

Simultaneous communications combines both spoken and manual modes to produce each word of an utterance. This study investigated the potential influence of alterations in the temporal structure of speech produced by inexperienced signers during simultaneous communication on the perception of final consonant voicing. Inexperienced signers recorded words that differed only in the voicing characteristic of the final consonant under two conditions: (1) speech alone and (2) simultaneous communication. The words were subsequently digitally edited to remove the final consonant and played to 20 listeners who, in a forced-choice paradigm, circled the word they thought they heard. Results indicated that accurate perception of final consonant voicing was not impaired by changes in the temporal structure of speech that accompanied the inexperienced signers' simultaneous communication.

Female↗

Voice onset time in speech produced by inexperienced signers during simultaneous communication.

This study investigated sentence duration and voice onset time (VOT) of plosive consonants in words produced during simultaneous communication (SC) by inexperienced signers. Stimulus words embedded in a sentence were produced with speech only and produced with SC by 12 inexperienced sign language users during the first and last weeks of an introductory sign language course. Results indicated significant differences between the speech and SC conditions in sentence duration and VOT of initial plosives at both the beginning and the end of the class. Voiced/voiceless VOT contrasts were enhanced in SC but followed English voicing rules and varied appropriately with place of articulation. These results are consistent with previous findings regarding the influence of rate changes on the temporal fine structure of speech (Miller, 1987) and were similar to the voicing contrast results reported for clear speech by Picheny, Durlach, and Braida (1986) and for experienced signers using SC by Schiavetti, Whitehead, Metz, Whitehead, and Mignerey (1996).

Adult↗

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

This study investigated temporal characteristics of speech produced during simultaneous communication (SC) by inexperienced signers. Recordings of stimulus words embedded in sentences produced with speech-only versus SC were made by 12 students during the first and last weeks of an introductory sign language course. Results indicated significant temporal differences between speech-only and SC conditions during both the first week and the last week of the class. Inexperienced signers appeared to sign between words in SC during the first week of the class, thereby extending interword intervals. At the last week of the class, they appeared to shift toward simultaneously signing while producing the words, thereby elongating segmental temporal characteristics, such as vowel duration. The specific temporal differences between SC and speech-only conditions were consistent with previous findings regarding the effect of SC on temporal characteristics of speech with experienced signers.

Communication↗

Effect of vowel environment on fricative consonant duration in speech produced during simultaneous communication.

This study investigated the effect of vowel environment on fricative consonant duration in contextual speech produced during simultaneous communication (SC). Previous studies (Schwartz, 1969) of vowel influences on consonant duration supported the notion of anticipatory scanning, in which final vowel targets influence the duration of preceding fricative consonants. Ten normal-hearing, experienced sign language users recorded palatal and alveolar fricatives produced in four vowel environments in contextual sentences under SC and speech-only (SO) conditions. Results indicated longer sentence durations for SC than for SO, and significant effects of vowel context on fricative consonant duration in contextual speech in both SC and SO conditions that revealed similar anticipatory scanning effects as seen in previous studies. These data confirm previous research indicating that the temporal alterations produced by simultaneous communication do not involve violations of the temporal rules of English speech.

Adult↗