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Biomedical subjects

J Gandour

Publications and source records attributed to J Gandour.

54 records · Page 3Linked to original sources
PubMed1984

Prosodic disturbance in aphasia: vowel length in Thai.

The aim of this study is to determine to what extent a phonologically contrastive function of the prosodic feature of length is resistant to impairment in aphasia. The language chosen for investigation is Thai, a language which contrasts short and long vowels. Subjects included two Broca aphasics, one transcortical motor aphasic, one Wernicke aphasic, one conduction aphasic, one nonaphasic right-brain-damaged patient, one nonaphasic cerebellar dysarthric patient, and five normal controls. The subjects read a list of words containing short and long vowels. Vowel durations were measured from spectrograms. The results showed that the timing of vowel duration for signaling the contrast between short and long vowels remains relatively intact in nonfluent as well as fluent aphasic patients. These data are brought to bear on issues concerning the specialization of the left hemisphere for temporal processing, the contribution of the right hemisphere to the processing of nonaffective components of prosody, the nature of prosodic disturbance in Broca's aphasia and cerebellar dysarthria, and the separate disruption of prosodic features.

Adult↗
PubMed1984

On describing idiosyncratic phonologic systems.

A phone distribution procedure for analyzing idiosyncratic phonologic systems in children is applied to a phonologically impaired child's distribution of alveolar and velar stops. Results show that these stops occur in complementary distribution: Alveolar stops occur before high vowels and velar stops occur before nonhigh vowels. It is further demonstrated that phonologic process analysis fails to reveal this unusual distribution of alveolar and velar stops. Thus, it is argued that phonologic process analysis must necessarily be supplemented by other procedures capable of detecting and describing unusual distribution patterns in order to achieve an accurate clinical diagnosis and to select the most appropriate target for a successful clinical treatment program.

Child, Preschool↗
PubMed1984

Tonal confusions in Thai patients with sensorineural hearing loss.

In a tone language, every syllable or word may have a distinctive pitch pattern as part of its phonemic composition. This study examined the extent and nature of impairment in the perception of phonemic tones by hearing-impaired listeners in Thai, a tone language that has five phonemic tones. Seventy-six subjects were assigned to four listener groups: normal-hearing (n = 21), mild-hearing-loss (n = 21), moderate-hearing-loss (n = 26), and severe-hearing-loss (n = 8). Five Thai words differing only in tone were presented for identification in both natural speech and synthetic speech versions. Results from the phonemic identification tests indicated that tonal identification is affected by the presence of sensorineural hearing loss. In particular, the number and often the type of tonal confusions made by Thai hearing-impaired listeners varied with the extent of hearing loss for both natural and synthetic speech versions. In contrast to previous findings on the patterns of consonant and vowel confusions in hearing-impaired listeners, the patterns of tonal confusions in hearing-impaired listeners can be related to the degree of hearing loss.

Adult↗
PubMed1984

Production of intonation and contrastive stress in electrolaryngeal speech.

Acoustical investigations of intonation and contrastive stress patterns in speech produced with electronic artificial larynges were completed. High-quality tape recordings of sentences spoken by 4 normal speakers, 3 users of the Western Electric 5A electrolarynx, and 2 users of the Servox electrolarynx were subjected to acoustic analysis. All electrolarynx users distinguished stressed from unstressed syllables by varying the duration of syllables and contiguous pauses. One Western Electric 5A speaker also controlled fundamental frequency. This speaker distinguished statements from questions by varying the rate and extent of the initial rising portion of fundamental frequency contours. Findings are interpreted in relation to their implications for clinical intervention and in terms of suggestions for improved design of artificial larynges.

Humans↗
PubMed1983

Identification of tonal contrasts in Thai aphasic patients.

In tone languages pitch variations (tones) serve to distinguish the lexical meanings of words. This study was conducted to examine the extent and nature of impairment in the perception of tones by aphasic patients who were monolingual speakers of Thai, a tone language which has five contrastive tones (mid, low, falling, high, rising). Six subjects participated in the study: two Broca aphasics, one transcortical motor aphasic, one conduction aphasic, one right brain-damaged nonaphasic, and one normal control. Three sets of stimuli (two real-speech, one synthetic-speech) were presented for identification, each set containing five Thai words minimally distinguished by tone. Results of the perception tests indicated that the performance of all four left brain-damaged aphasics differed significantly from that of the normal control, while the performance of the right brain-damaged nonaphasic did not. The normal performance of the right brain-damaged nonaphasic patient on this tone identification task suggests that deficits in the perception of tone exhibited by left brain-damaged patients can be attributed specifically to pathology in the language dominant hemisphere rather than to a general brain-damage effect. No difference in performance among the left brain-damaged patients could be attributed to a specific type of aphasic syndrome. The pattern of tonal confusions of the aphasics in comparison to that of normals suggests that their deficit is primarily quantitative rather than qualitative. Although two (mid, low) of the five tones accounted for a large percentage of the aphasics' errors, no uniform rank order of tones in terms of identifiability could be established across aphasic subjects, which suggests that their deficit is general to all five tones rather than selective to individual tones.

Adult↗
PubMed1983

Perception of intonational contrasts in alaryngeal speech.

The achievement of intonational contrasts by 4 normal and 16 laryngectomized speakers was assessed in this project. The laryngectomized subjects represented four clinical subgroups of alaryngeal speech: esophageal, tracheoesophageal, Western Electric #5 electrolarynx, and Servox electrolarynx. High-quality tape recordings of each subject's productions of two pairs of sentences (Bev loves Bob) spoken in statement and question from were presented to 40 listeners for evaluation using a two-interval-alternative-forced-choice procedure. Intonational contrasts were achieved in a highly effective manner by the normal, esophageal, and tracheoesophageal speakers. In contrast, users of electronic artificial larynges were generally unable to achieve these intonational distinctions except for one user of the Western Electric #5 electrolarynx.

Adult↗
PubMed1983

Perception of lexical stress in alaryngeal speech.

This project was a perceptual investigation of lexical stress in alaryngeal speech. The ability of alaryngeal speakers to signal lexical stress in American English was assessed by obtaining high-quality tape recordings of noun-verb oppositions (e.g., 'insult vs. in'sult) from four normal and 16 laryngectomized speakers using four different types of alaryngeal speech. The recordings of these words were presented to 30 listeners for perceptual evaluation using a two-interval-forced-choice procedure. As expected, the four normal speakers achieved high (93% or above) levels of stress contrast. Lexical stress contrasts were also achieved at a high level of proficiency (88% or above) by all four esophageal speakers, all four tracheoesophageal speakers, one of four users of the Western Electric electrolarynx, and two of four users of the Servox electrolarynx. Lexical stress contrasts were realized in a less (82-86%) but reasonably effective manner by one Western Electric user and two Servox users. The findings were interpreted to highlight the contributions that study of clinical samples may make to investigations of speech production and speech perception.

Adult↗
PubMed1981

The nondeviant nature of deviant phonological systems.

Few studies of children with defective speech or deviant phonologies have gone beyond the level of phonetic representation in limited environments. The Lorentz (1976) study of Joe, a 4.5-yr-old child with a phonological disorder, is exceptional inasmuch as underlying phonemic representations and phonological rules are posited in addition to the surface phonetic representations. However, his analysis crucially depends on morphosyntactic information that cannot be independently justified. A reanalysis of Joe's data within Kahn's (1976) syllable-based model of generative phonology reveals that the child's phonological rules are syllabically conditioned exclusively. In particular, the application of certain rules is found to depend on whether or not an internal syllable boundary is present within a polysyllabic word. In the course of the reanalysis, issues concerning naturalness of individual phonological rules, ordering relations between pairs of rules, feature systems, the phonological representation of double-articulated consonants, and the role of the syllable as element in phonological descriptions are discussed. Paradoxically, Joe's phonological system is found to be "normal," as measured in terms of the above-mentioned linguistic parameters, yet his speech output is "abnormal," as measured against the adult norm.

Child, Preschool↗
PubMed1981

On the relationship between vowel height and fundamental frequency: evidence from esophageal speech.

Data from esophageal speech produced by laryngectomized patients was used to provide a reexamination of major contemporary hypotheses advanced to account for intrinsic variation in vowel fundamental frequency (F0). 4 speakers provided recordings of 15 tokens of three CVC syllables [hid, hud, had]. Analysis of these utterances revealed that intrinsic variation in vowel F0 is clearly evident in esophageal speech. These findings were interpreted (1) to support neither the source-tract coupling nor the tongue-pull hypotheses and (2) to highlight the need to test alternative explanations to account for the intrinsic variation in vowel F0.

Aged↗
PubMed1976

Measuring larynx movement in standard Thia using the cricothyrometer.

Vertical movement of the larynx during connected speech was investigated in Standard Thai - a language that has five phonologically contrastive tones. The effects of pitch, consonant phonation-type, vowel quality, tonal categories, and position in the utterance were determined. Utterance position was found to be the factor most clearly associated with variations in larynx movement. The occurrence of an overall rise-fall pattern of larynx movement distributed over utterances of varying pitch patterns leads to the conclusion that larynx height is not a principal factor regulating pitch in connected speech. Implications for models of pitch production, distinctive features for tone, theories on the historical development of tone and the role of larynx movements in the production of consonants and vowels are discussed.

Adult↗