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Duration measurements associated with rhythmic aspects of speech produced by one Thai esophageal speaker were compared to previously published identical measures for normal Thai speakers. Measures of central tendency and variability were taken of the duration of syllables, pauses, phrases, and interstress intervals. Despite a slower-than-normal overall speaking rate and a shorter-than-normal phrase length, the esophageal speaker was able to maintain normal relative temporal relations among syllables within phrases. Although his speech was dysrhythmic at the overall discourse level, it was rhythmic at the phrase level. Findings are interpreted to highlight the importance of differentiating features of alaryngeal speech that are common across languages from those that are specific to particular languages.

Five laryngectomized, tracheoesophageal (TE) speakers completed a series of phonatory tasks developed to assess (a) aerodynamic and acoustic properties of TE voice and (b) aerodynamic and myoelastic contributions to the mediation of fundamental frequency change. These TE speakers' voices were characterized by increased trans-source airflow rates, comparable source driving pressures, and decreased airway resistances in comparison with standard esophageal speakers. TE speakers were capable of adjusting their voicing sources on a myoelastic basis to influence Fochange. This result, coupled with findings that confirm aerodynamic contributions to TE phonation, are intepreted to suggest that TE voice production should be regarded as an aerodynamic-myeolastic event. Findings are integrated with existing data to highlight fundamental differences among TE, esophageal, and normal voice production.

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.

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 form 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.

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., 'insultvs. 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 investigatons of speech production and speech perception.

Emperical and theoretical approaches to the assessment of Blom-Singer tracheoesophageal puncture prosthesis performance are described in this paper. The results of empirical studies provide new insights about the behavior of Blom-Singer devices. Namely, the overall average resistance (about 126 cm H2O/LPS) of these devices stems from two major factors: air entrance and air exit effects. The magnitudes of airway resistance for each of these factors and the relative contribution each factor makes to the total airway resistance of these prostheses are delineated. The performance of these devices and modifications thereof are shown to be characterized and predicted quite well using a one-dimensional, spring-constant mathematical model.

Acoustical investigations of intonation and contrastive stress patterns produced by laryngectomized patients using esophageal and tracheoesophageal speech were completed. High-quality tape recordings of sentences spoken by four normal, four esophageal, and three tracheoesophageal speakers were subjected to fundamental frequency, duration and intensity analysis. Results indicated that some esophageal and tracheoesophageal speakers were able to manipulate, at comparable relativemagnitudes, the same acoustic properties normal speakers use to produce intonation and contrastive stress patterns.

This project was a perceptual investigation of contrastive stress in alaryngeal speech. The ability to signal contrastive stress in American English was assessed by obtaining high quality tape recordings of sentence production from four normal and sixteen laryngectomized speakers using four different types of alaryngeal speech. The recordings of these sentences, paired on the basis of differences in the location of contrastive stress, were presented to forty listeners for perceptual evaluation of stress location using a two-interval-forced-choice procedure.

Broad-band masking of speech was used to assess the effects that broad-band masking noise had upon the recognition of consonants and vowels produced by esophageal speakers. Procedures were developed to compare the articulation functions of superior esophageal speech with those of normal speech under comparable levels of masking noise. Within the range of speech-to-noise ratios studied, articulation functions for vowels were essentially the same for esophageal and normal talkers (4% per dB). With respect to consonants, the intelligibility scores for esophageal speech were 12 to 14% lower than for normal speech under adverse noise conditions. Gains in the consonant articulation functions were 2.5%/dB and 4%/dB for normal and esophageal talkers, respectively. For adverse noise conditions, the lowered consonant scores for esophageal speakers were the result of poorer than normal intelligibility for liquid-glides and nasal and, secondarily, for stop consonants. Additional differences between the intelligibility characteristics of esophageal and normal speech were found in word-position and voicing features.

This study assessed the realization of junctural contrasts by normal and esophageal speakers. Ten normal subjects and ten laryngectomized subjects using esophageal speech provided high quality tape recordings of three productions of five ambiguous two-word phrases. These recordings were presented to forty, listeners for evaluation using a Two Interval Forced Choice procedure. Both normal and esophageal speakers realized junctural contrasts in ambiguous phrases in a highly effective manner. Significant differences in listeners' overall perception of juncture locus were found for talker group and individual speaker main effects. The findings of this project were interpreted to highlight the contribution that study of clinical samples may make to questions in linguistic theory, speech production, and speech perception. Finally, the direct clinical relevance of the procedures and results are discussed.

The broad objective of the present project was to assess the degree to which esophageal speakers are able to control voice fundamental frequency. Three male esophageal speakers and four age-matched normal speakers were used in a vocal pitch matching task to elicit f0levels. Average differences in fundamental frequency between the individual targets and productions were comparable for esophageal and normal talkers, The frequency variation associated with pitch matching by esophageal speakers was 1.5 to 8 times greater than that by normal talkers, The results were interpreted to support (1) the hypothesis that esophageal speakers were less proficient in controlling the steady-state attributes of their voicing source and vocal output; and (2) the view that esophageal speakers exhibit reduced intentional control over voice fundamental frequency.

The voice onset times (VOT) of a large number of stop-consonant initiated syllables produced by esophageal and normal speakers were measured. Esophageal speakers systematically varied VOT during the production of speech-sound categories with the same manner of production. Average voice onset times associated with the production of prevocalic voiceless stops of esophageal speakers were significantly shorter than those of normal speakers, while talker-group comparisons associated with the production of voiced prevocalic stops were nonsignificant. Voice onset times of both esophageal and normal speakers were differentially sensitive to place of articulation. Findings are discussed in terms of furthering current understanding of how effectively esophageal speakers achieve important phonological contrasts.

Audiotape recordings of sustained vowels produced by nine esophageal speakers were subjected to acoustic and perceptual analysis. Results indicated that (1) the magnitude of vocal jitter present in the vowels was substantially larger than that observed in normal speakers and speakers with laryngeal/vocal disturbance, (2) listeners could reliably rate the severity of vocal roughness in the vowels, (3) voices of esophageal speakers were characterized by varying degrees of vocal roughness, and (4) mean fundamental frequency, mean jitter, or jitter ratio measures did not serve as useful predictors of the perceived severity of vocal roughness. These findings are interpreted to suggest that the mechanism esophageal speakers employ to regulate fundamental frequency is substantially different from that employed by normal speakers and that the identity of physical variables underlying the perception of roughness severity in naturally produced human speech is not well understood.

The duration of a large number of representative vowels produced by 10 esophageal and nine normal speakers were measured. Overall vowel durations of esophageal speakers were consistently longer than those of normal speakers, indicating that esophageal speakers do not compensate for their striking diminution in air supply for speech by decreasing vowel duration. The differences in the vowel duration characteristics between normal and esophageal speakers were observed to vary systematically as a function of the voicing features of their consonant environments. Specifically, the durations of vowels of esophageal speakers spoken within voiceless consonant environments were consistently longer than those spoken in similar contexts by normal speakers. There were no significant differences between the average durations of vowels spoken by normal and esophageal speakers within voiced consonant environments. The observation that the durations of vowels produced by esophageal speakers differed significantly as a function of the voicing features of their consonant context was interpreted to support the belief that inherent, rule-governed durational features of English are retained following laryngeal amputation.

An intensive study of a normal-speaking subject, proficient in the use of buccal speech, was conducted. With respect to voice fundamental frequency variability, phonation time, and speaking rate his buccal speech characteristics compared favorably with those reported for excellent esophageal speakers. However, the reduced intelligibility of his buccal speech on rhyme-test words, the high average fundamental frequency of his buccal voice, and his conspicuous buccal gestures during speech represent distinct vocal liabilities.

The fundamental frequency (f0) characteristics of 28 esophageal speakers measured on a wave-by-wave basis were compared with the f0 characteristics of these same speakers measured on an averaging basis. Fundamental frequency mean, standard deviation, and mid-90% range values measured on an averaging basis correlate strongly with those obtained on a wave-by-wave basis. The mean fundamental frequency for esophageal speakers did differ significantly (p< 0.001) as a function of measurement technique. This difference was small (0.75 semitones) and does not account for the 20- to 30-Hz difference in average fundamental frequency of esophageal speech reported by various investigators. The implications of these findings are discussed.

Highly representative esophageal vowels (N = 191) selected from a listening experiment were subjected to formant frequency analysis. The results of this acoustic analysis showed that: (1) mean vowel formant frequencies for female esophageal speakers were higher than for males, (2) the changes in formant frequency from vowel to vowel were systematic and were essentially the same for normal and esophageal speakers, and (3) average vowel formant frequency values for esophageal speakers were consistently higher than those reported for normal speakers (Peterson and Barney, 1952). The data strongly support the hypothesis that removal of the larynx does alter vocal-cavity transmission characteristics. A reduction in effective vocal tract length for laryngectomized persons using esophageal speech is suggested.

This study investigated the ability of listeners to identify the sex of esophageal talkers on the basis of voice recordings. Recognition data are provided for 15 female and 18 male esophageal talkers. In general, the results support the hypothesis that naive listeners can reliably and accurately identify the sex of esophageal talkers from voice samples.

The purpose of this study was to define variation in /s/ articulation associated with differences in incisor dentition. Articulatory relationships, defined by cephalometric films, were studied in normal speakers with normal occlusion and complete dentition, normal speakers with normal molar relationships and missing maxillary incisors, and /s/ defective speakers with normal molar relationships and missing maxillary incisors. Adequacy of /s/ articulation for the total sample of 39 children was determined by two separate auditory ratings. Significant differences between normal and defective /s/ articulation were related to the environmental characteristics of the anterior oral constriction. Speakers with defective /s/ articulation excessively fronted the tongue tip. Other differences were related to the antero-postero and vertical placement of the tongue tip, to the extent of mandibular protrusion-retrusion, and to the vertical position of the upper lip. There was no significant difference between children with normal and defective /s/ articulation in regard to the degree of vertical constriction between the midline of the tongue and dental-alveolar complex. These findings appear to be consistent with current physiological phonetic theory.