Jay W. Lerman

Perceptual and Acoustic Evaluation of Individuals with Laryngopharyngeal Reflux Pre- and Post-treatment

Thirteen individuals with laryngopharyngeal reflux (LPR) were studied pre- and post-treatment. The effect of treatment on perceptual ratings of voice quality and frequency and intensity measures was examined. Relationships between perceptual and acoustic parameters were assessed descriptively. Results showed a small, but significant improvement in the perception of voice quality post-treatment. No significant differences were found between pre- and post-treatment means for any of the acoustic measures except harmonics-to-noise ratio (HNR). Descriptive analyses showed some association between perceptual ratings and acoustic measures. Discussion of results focuses on severity of LPR.

Influence of Gender and Environmental Setting on Voice Onset Time

The influence of gender and environmental setting on voice onset time (VOT) was examined. Participants produced six stop consonants paired with three vowels in a consonant + vowel (CV) context. Recordings were made when participants were seated inside a sound booth (laboratory setting) and outside a sound booth (non-laboratory setting). Results of the analysis for VOT and CV duration indicated that females produced voiceless stops with significantly longer VOT durations than males in both settings. Both gender groups produced CV tokens with significantly longer duration in the laboratory setting; however, females continued to produce CV tokens with longer duration in the non-laboratory setting. Findings suggest that differences in the vocal anatomy between genders may account for some but not all differences in temporal measures of speech production. Sociophonetic factors, such as speaking style, may also contribute to gender differences in speaking behavior.

A study of sentence stress production in Mandarin speakers of American English

Acoustic characteristics of American English sentence stress produced by native Mandarin speakers are reported. Fundamental frequency (F0), vowel duration, and vowel intensity in the sentence-level stress produced by 40 Mandarin speakers were compared to those of 40 American English speakers. Results obtained from two methods of stress calculation indicated that Mandarin speakers of American English are able to differentiate stressed and unstressed words according to features of F0, duration, and intensity. Although the group of Mandarin speakers were able to signal stress in their sentence productions, the acoustic characteristics of stress were not identical to the American speakers. Mandarin speakers were found to produce stressed words with a significantly higher F0 and shorter duration compared to the American speakers. The groups also differed in production of unstressed words with Mandarin speakers using a higher F0 and greater intensity compared to American speakers. Although the acoustic differences observed may reflect an interference of L1 Mandarin in the production of L2 American English, the outcome of this study suggests no critical divergence between these speakers in the way they implement American English sentence stress.

Fundamental Frequency, Intensity, and Vowel Duration Characteristics Related to Perception of Cantonese Alaryngeal Speech

Fundamental frequency (F₀), F₀ contours, vowel duration, and intensity associated with Cantonese alaryngeal speech, and their relation to the perception of meaning were studied. Thirty adult male native Cantonese speakers participated in the study: 10 esophageal, 10 electrolaryngeal, and 10 laryngeal speakers. Results indicated that perceptually, listeners were able to identify what the Cantonese esophageal speakers were saying, particularly for words associated with high-level, low-falling and high-rising tonal contours. Acoustic analysis of the speech signals of the esophageal speakers indicated that intensity and durational data did not contribute to the perception of meaning. The F₀ contours appeared to be the acoustic cues associated with the signal that contributed most to the perception of meaning.

Perceptions of tonal changes in normal laryngeal, esophageal, and artificial laryngeal male Cantonese speakers.

Listeners were asked to identify six tonal variations in the production of the syllables /ji/ and /si/ produced by 10 normal laryngeal (NL), 10 standard esophageal (SE), and 10 Servox-type electrolarynx (EL) Cantonese speakers. The purpose of the present study was to determine if alaryngeal Cantonese speakers could differentiate meanings associated with different tone levels. Results indicated that listeners’ identification of the six tones for each syllable produced by the SE speakers was similar in pattern to those produced by the NL speakers of Cantonese. For both NL and SE speech, the high-level, low-falling, and high-rising tones were perceived more accurately than the mid-level, low-level, and low-rising tones. Identification of the six tones for each syllable as produced by the EL speakers was significantly poorer due to the limitations of the electrolarynx.

Some acoustic evidence for vocal abuse in adult speakers with repaired cleft palate.

Acoustic evidence for vocal abuse in adult speakers with cleft palate and hypernasality has not been reported. This study was undertaken to determine if there was acoustic evidence of inappropriate vocal fold adduction during stop consonant production in this population. The results indicated that spectrograms of speakers with cleft palate and severe hypernasality exhibited acoustic characteristics different from spectrograms of speakers without cleft palate and speakers with cleft palate and mild hypernasality. Specifically, voiceless stop productions of severe hypernasal speakers resembled voiced stop productions. Their vocal folds were inappropriately adducted to provide a constriction inferior to the inadequately functioning velopharyngeal port to minimize the nasal air leak. The acoustic evidence supports the hypothesis that a cause of vocal abuse in the cleft palate population is due to compensatory laryngeal valving activities secondary to severe hypernasality.

Some aerodynamic and acoustic characteristicsof acute laryngitis

The purpose of the present study was to describe the effects of acute laryngitis on some aerodynamic, acoustic, and perceptual measures. Eleven subjects with diagnosed acute laryngitis due to upper respiratory infection were recorded during a laryngitic episode and 1 week to 10 days after amelioration of the laryngitic condition. Fundamental frequency, values, collapsed across the five vowels, were significantly reduced in the laryngitic compared with the normal speaking condition. The decrease in fundamental frequency associated with acute laryngitis suggests an increase in the mass of the vocal folds. In addition, aerodynamic values differed significantly for the laryngitic condition compared with the normal speaking condition, suggesting the presence of laryngeal hypofunction. Perceptual data indicated that speakers in the laryngitic condition were judged to have a hoarse voice when compared with the normal speaking condition.

Speech acceptability and olfaction in laryngectomees

A number of hypotheses concerning the causal relationships and interrelationships between esophageal speech acceptability, olfactory abilities, and airflow volume in laryngectomees were tested. To assess the hypotheses, data were collected from 25 laryngectomees and comprised the following: (1) A measure of speech acceptability using a standard passage of prose; (2) odor identification test results in which 14 common odorants were used; (3) odor threshold test results in which an 11-step aqueous dilution series of l-butanol was used and: (4) a measure of nasal airflow volume in liters per minute. The null hypotheses linking speech acceptability, olfaction, and airflow volume were all tested and none of the path coefficients was significant. The results are discussed in relation to observations made by Gilchrist [Acta Otolaryngol. (Stockh.) 75:511-518 (1973)], who noted that those esophageal speakers who attained good speech maintained a greater sensitivity to smell. The findings in the present study do not support Gilchrists observations.

Acoustic examination of naturalistic modal and falsetto voice registers

Acoustic characteristics of sustained vocalizations produced in modal and falsetto voice registers are reported for a group of seven adult males. Analysis of the overall intensity of modal and falsetto registers indicated no significant differences between the two registers. However, analysis of the relationship in amplitude of the fundamental (Fo) to the amplitude of the corresponding harmonic (H2) revealed consistent differences between the two registers. During modal register, the amplitude of the Fo was consistently lower compared to H2, while the opposite trend was found for falsetto registers. Discussion focuses on the possible physiological explanations for the acoustic patterns observed in this study.

Speech segment duration measurements in adult speakers with repaired cleft palate and hypernasality

Consonant closure duration, vowel duration preceding word‐final stop consonants, and total VCVC utterance duration were measured in order to investigate if normal durations in these variables were exhibited in subjects with cleft palate and hypernasality. The data revealed no significant differences among three adult subject groups (noncleft, repaired cleft with mild hypernasality, and repaired cleft with severe hypernasality) on any of the duration measurements investigated, suggesting that speech timing for these features were not significantly altered by the presence of the nasal air leak. Speakers in the two hypernasal groups, however, showed smaller differences between vowel durations in voiced and voiceless stop environments than did speakers without cleft palate. There were significant differences among groups in durational cues between vowel types and between voicing features of stop consonants, both of which were in agreement with previous research.