Peak Intraoral Pressure Research Articles

Task-Dependent Velopharyngeal Timing in Singers with Classical Training

This study examined velopharyngeal (VP) timing characteristics during singing and speaking tasks among singers with varying degrees of classical training. Pressure-flow data were collected when eight soprano singers sang and spoke the phrase, "I will say hamper," at different pitch (C4 and C5) and loudness levels (soft, medium, and loud). VP aerodynamic variables (VP gap, peak nasal airflow [NF], and peak intraoral pressure [OP]) and timing variables (NF pulse duration, OP pulse duration, and total duration of the /mp/ sequence) were of particular interest. Results of linear mixed-effects models showed no significant main effect of task type (speaking vs. singing) on VP aerodynamic variables. Task type was found to have a statistically significant main effect on OP pulse duration (F(1, 77) =27.590, P<0.05) and total duration of the /mp/ sequence (F(1, 75.034) =17.895, P<0.05), with both durational measures significantly shorter for singing (OP pulse duration: 200ms, total duration of the /mp/ sequence: 212ms) than for speaking (OP pulse duration: 228ms, total duration of the /mp/ sequence: 238ms). The pitch had a significant main effect on OP pulse duration, with C5 (207ms) significantly shorter than C4 (221ms). Loudness was found to have no significant main effects on any of the VP timing variables. VP timing patterns significantly differed between the singing and the speaking task. Specifically, the singers employed a quick OP pulse rise time, which shortened OP pulse duration as well as the total duration of the /mp/ sequence during the singing task in comparison to the speaking task. Robust VP timing patterns observed during singing may reflect the singers' skilled control of the VP mechanism to achieve functional and esthetic goals.

Characteristics of phonation in women who produce voiced versus voiceless /h/

Production of the consonant /h/ typically involves a vocal-fold abduction gesture. Although /h/ is traditionally described as voiceless in English, voiced allophones also occur. Our recent work has described the phonatory behavior of women who produce a mixture of voiced and voiceless /h/; our results suggested speaker-specific patterns of the factors that lead to devoicing. This study characterizes the behavior of normal women who produce exclusively voiced /h/ and compares it to those who produced both voiced and voiceless /h/. Measures of baseline (dc) airflow are used as an index of abduction degree; peak intraoral pressures during adjacent /p/ closures provide a measure of subglottal pressure; and pulse-by-pulse measures are made of f0 and pulse amplitude (ac flow) around the /h/ abduction gesture. Multidimensional analyses are carried out within speakers to determine how these vocal parameters are related. We expect that women who produce only voiced /h/ will differ from those who devoice some /h/ productions in the parameters that facilitate phonation, such as higher subglottal pressures, smaller abduction degrees, and reduced vocal-fold tension as reflected in f0 measures. Based on our previous findings, however, we also expect individual variation in the phonatory settings that produce voiced /h/. [Work supported by NIH.]

Multiparametric Evaluation of Dysphonic Severity

In recent years, the multiparametric approach for evaluating perceptual rating of voice quality has been advocated. This study evaluates the accuracy of predicting perceived overall severity of voice quality with a minimal set of aerodynamic, voice range profile (phonetogram), and acoustic perturbation measures. One hundred and twelve dysphonic persons (93 women and 19 men) with laryngeal pathologies and 41 normal controls (35 women and six men) with normal voices participated in this study. Perceptual severity judgement was carried out by four listeners rating the G (overall grade) parameter of the GRBAS scale. The minimal set of instrumental measures was selected based on the ability of the measure to discriminate between dysphonic and normal voices, and to attain at least a moderate correlation with perceived overall severity. Results indicated that perceived overall severity was best described by maximum phonation time of sustained /a/, peak intraoral pressure of the consonant-vowel /pi/ strings production, voice range profile area, and acoustic jitter. Direct-entry discriminant function analysis revealed that these four voice measures in combination correctly predicted 67.3% of perceived overall severity levels.

Intraoral pressure and velopharyngeal function.

The objective of this study was to determine the influence of velopharyngeal (VP) inadequacy on respiratory speech compensations. The pressure-flow technique was used to measure pressure, airflow, and timing variables associated with VP closure during the production of the initial plosive consonant /p/ in a series of the utterance "papa." The study was conducted in the speech and breathing laboratory of the UNC Craniofacial Center. Eighty-two subjects with cleft lip and/or palate were assessed. The subjects were divided into two groups, those with adequate VP closure (VP size <.010 cm2) and those with inadequate VP closure (VP size >0.10 cm2). The adequate group was comprised of 62 subjects, and 20 subjects were categorized as inadequate. Peak intraoral pressure decreased in the inadequate group, but the difference was not significant. Nasal airflow increased (p < .01), but duration of the pressure pulse was the same for both groups. The area under the pressure curve decreased for the inadequate group (p = .04). These data contrast with previously reported published data using /p/ in the utterance "hamper." This suggests that phonetic context influences the compensatory response to velopharyngeal inadequacy. Additionally, while the findings are somewhat similar to studies that involved noncleft subjects whose oral airway was suddenly vented during the production of /p/, there is enough difference to suggest that learning also affects the compensatory outcome.

Temporal Characteristics of Velopharyngeal Function in Children

This investigation was designed to examine the performance of children with normal speech on temporal aspects of aerodynamic tasks related to velopharyngeal closure.The investigation was a descriptive evaluation of variability in aerodynamic features related to velopharyngeal function during multiple repetitions of the word "hamper."Children without speech or velopharyngeal difficulties were seen in an experimental laboratory setting for the evaluation procedures.Twenty-seven subjects were recruited for the experiment. Three subjects were rejected because of behavioral difficulties, and the remaining 24 subjects were subdivided into 4 groups of 6 children (3 males and 3 females) aged 3, 6, 9, and 12 years. The children, who were from local schools and day care centers, volunteered to participate in the experiment. All of the children had age-appropriate speech, language, and hearing abilities, as determined by screening tests administered by one of the examiners (L.T.).Mean and variability of pressure-flow measures of peak intraoral air pressure and peak nasal airflow and the temporal measures accompanying each air pressure or airflow pulse were evaluated for the age groups of children examined in the experiment.The aerodynamic procedures employed to evaluate velopharyngeal closure during speech were reliable for use with young children. There was a numerical trend toward decreased duration of the temporal parameters with increasing age. Thus, children demonstrated durational values similar to those previously reported for normal-speaking adults. In general, peak oral air pressure and nasal airflow values were like those of previous investigations and demonstrated low variability across all age groups of children tested.The data from the present investigation provide a preliminary base for comparison of temporal features of velopharyngeal closure for the aerodynamic evaluation of children with impaired velopharyngeal function.

Some observations of the tense–lax distinction theory with reference to English and Korean

A series of experiments with 13 subjects in total and with /VCV/, /CVC/, /CVCVCV/, and /CVCVC/ words, using various techniques, was undertaken to verify the hypothesis that the speaker may select at least one of muscles involved in the articulation of a phoneme so that either timing or amplitude variable and/or both of the selected muscle(s) could distinguish /p/ from /b/ in English and /ph, p′/ from /p/ in Korean. The English /p/ and the Korean aspirated /ph/ and unaspirated /p′/ were tense, and the English /b/ and the Korean unaspirated /p/ lax. Findings: (1) The EMG data, obtained from the orbicularis oris superior muscle and the depressor anguli oris muscle, supported the tense–lax opposition, except for one English subject in stressed syllables; (2) The leveled peak intraoral airpressure, an output of the synchronized respiratory muscle activities during bilabial stops, backed up the tense–lax distinction, except for one English subject in unstressed syllables, and there was intermuscle compensation between the labial muscle activities and the respiratory muscle activities; (3) The data of the maximum lingual contact in alveolar stops also supported the tense–lax distinction theory. Thus it can be said that the hypothesis has been verified in both languages.

Tongue surface displacement during bilabial stops.

The goals of this study were to characterize tongue surface displacement during production of bilabial stops and to refine current estimates of vocal-tract wall impedance using direct measurements of displacement in the vocal tract during closure. In addition, evidence was obtained to test the competing claims of passive and active enlargement of the vocal tract during voicing. Tongue displacement was measured and tongue compliance was estimated in four subjects during production of /aba/ and /apa/. All subjects showed more tongue displacement during /aba/ than during /apa/, even though peak intraoral pressure is lower for /aba/. In consequence, compliance estimates were much higher for /aba/, ranging from 5.1 to 8.5 x 10(-5) cm3/dyn. Compliance values for /apa/ ranged from 0.8 to 2.3 x 10(-5) cm3/dyn for the tongue body, and 0.52 x 10(-5) for the single tongue tip point that was measured. From combined analyses of tongue displacement and intraoral pressure waveforms for one subject, it was concluded that smaller tongue displacements for /p/ than for /b/ may be due to active stiffening of the tongue during /p/, or to intentional relaxation of tongue muscles during /b/ (in conjunction with active tongue displacement during /b/).

Intraoral air pressure of alaryngeal speakers during a no-air insufflation maneuver

Intraoral air pressure was recorded during the production of the consonant cognate pairs /p/-/b/, /t/-/d/, and /s/-/z/ by eight esophageal speakers. These consonants were combined with the vowel /a/ to form CV, VCV, and VC syllables and produced under two experimental conditions: after the insufflation of air and without air insufflation. The purpose was to determine if the voiced-voiceless pressure difference associated with the production of cognate pairs would occur in the absence of an insufflated air flow source. The results revealed that peak intraoral air pressure magnitudes were significantly greater following the insufflation of air than without it. Moreover, the voiceless consonants were generally produced with greater peak air pressures than the voiced consonants under both experimental conditions, although not all contrasts were significantly different. Finally, peak air pressure magnitudes were significantly more variable in the air insufflation condition. The finding that the esophageal speakers exhibited a pressure difference relative to voicing in the absence of an insufflated air flow source provides support to the concept that intraoral air pressure may be an important variable in regulating and controlling consonant production.

Voicing distinction in esophageal speech.

In order to analyze the articulatory ability of skilled esophageal speakers in terms of the voicing distinction in consonants, perceptual, acoustical and physiological studies were conducted. It was found that voiced-voiceless confusion was only 10.5% on average in the present subjects. Acoustical analysis indicated that voice onset time (VOT) values in word-initial position and the presence or absence of voicing in word-medial position were most important cues for the voicing distinction of consonants in esophageal speech. Fiber-optic and photoglottographic examinations revealed that there was a transient opening of the neoglottis for the production of voiceless sounds, while it stayed closed for voiced sounds. Immediately before the period of voicelessness, surface EMG obtained from the anterior neck appeared to show transient activation. There was a tendency that peak intraoral pressure values for the voiceless stops were significantly higher in the esophageal speakers than in the normal subject, whereas the values for voiced cognates were rather close to those of the normal.

Intraoral pressure in the evaluation of laryngeal function.

The difference in peak intraoral pressure between the consonants /p/ and /b/ (abbreviated as Pr./p-b/) showed a significant correlation with the transglottal pressure during consonant /b/ production. The values of Pr./p-b/ in subjects with vocal fold palsy were smaller than those in subjects with a cancer or polyp. The values of Pr./p-b/ divided by the estimated subglottal pressure in the subjects with cancers showed different distributions from those in subjects with palsies, polyps and in normal subjects. These parameters have potential benefit for the evaluation of pathological conditions of the glottis, especially for insufficient closure of the glottis and high stiffness of the vocal folds.

Clinical report on preliminary data on intraoral pressure in the evaluation of laryngeal pathology

<h2>Summary</h2> The consonant /b/, when surrounded by vowels, is accompanied by vocal fold vibration even during occlusion of the supraglottal cavity. Since the voicing of /b/ involves a relatively loose closure of the glottis and smaller amplitudes of vibration than those observed during the production of vowels, the transglottal pressure during /b/ production approximates that of the oscillation threshold pressure. Since the intraoral pressure of /p/ production is approximately equal to subglottal pressure of the surrounding vowels, the differences in peak intraoral pressure between the productions of /i:pi:/ and /i:bi:/ can be assumed to reflect the transglottal pressure during /b/ production. In a clinical investigation, the differences in the peak intraoral pressures of /i:pi:/ and /i:bi:/ were found to be higher in conditions typified by stiff vocal folds, such as laryngeal cancer and partial laryngectomy, than in those typified by flaccid folds, such as vocal cord polyp and palsy. This suggests that the intraoral pressure differences between /i:pi:/ and /i:bi:/ may constitute a parameter indicative of vocal cord stiffness

The effects of auditory feedback on the regulation of intraoral air pressure during speech

Previous experimental evidence has been interpreted as support for regulation of both acoustics and aerodynamics during speech production. One recent perspective is that although speech acoustics may be manipulated, regulation of aerodynamics is a central component of the processes that produce speech. From this perspective, it has been suggested that aerodynamic regulation is given priority over perceptual accuracy. The experiment attempted to test this hypothesis by forcing speakers into a choice between aerodynamic and acoustic regulation. The intensity level of frication (embedded in a carrier phrase) was selectively amplified or attenuated and fed back to the speaker on line. Intraoral air pressure was recorded in order to assess whether or not perturbed auditory feedback would result in aerodynamic compensation. Although compensatory changes in peak intraoral air pressure, pressure duration, and pressure curve area were seen in response to 30-dB alterations of frication, no systematic effects were seen for smaller auditory manipulations. Further, the compensations were less than what one might expect from a system controlling auditory output. Explanations of these findings and their implications for the control of speech production are offered.

Respiratory response to oral flow and pressure perturbations during speech

Evidence for the regulation/control hypothesis of Warren for speech aeromechanics [Cleft Palate J. 23, 251–260 (1986)] was observed in nine normal men who produced /pʌ/ and /si/ under conditions in which a translabial device released intraoral pressure during /p/, and bite blocks opened the anterior bite artificially during /s/. Intraoral pressures, oral flows, and respiratory volumes associated with utterance were the dependent variables. For /p/, intraoral pressure decreased and translabial air leakage increased as bleed orifice area increased, but mean peak intraoral pressure never fell below 4 cm H2O. For /s/, mean oral flow increased slightly as the anterior bite was opened, but mean peak oral pressure did not vary significantly from control values. Mean flow on the postconsonantal vowels did not vary significantly across the experimental conditions. There were no significant differences among mean inspiratory volumes within or across translabial bleed conditions, nor within or across bite-Mock conditions. Expiratory volume increased significantly as bleed orifice area increased, but not as bite-block size increased. These data may reflect the regulation control options inherent in each condition. The respiratory system alone could be relied upon to maintain intraoral pressure within requisite limits for speech during the bleed conditions; during the bite-block trials, speakers could employ increased respiratory drive, structural adjustments of the sibilant orifice, or both, to compensate for aeromechanical perturbation introduced by the blocks. [Work supported by AHFMR.]

Variations in velar position over time: a nasal videoendoscopic study.

Changes in velar position during production of nonnasal speech in two adults were measured using field-by-field videoendoscopic tracking procedures. The data suggested that the changes in velar position were coordinated with syllable production. Peak velar displacement occurred during maximum oral closure for oral consonant production and was followed by lowering of velar position during vowel production. This pattern of velar movement was not altered by changes in speaking rate or by jaw fixation. The timing of peak velar elevation relative to peak intraoral air pressure and peak jaw elevation was also examined. Timing of peak velar displacement was statistically associated with timing of peak intraoral air pressure in one subject. The data are discussed with regard to the potential value of studying variations in velar position during nonnasal speech in patients with marginal velopharyngeal incompetence.

Variability differences in the speech production in two age groups of adult females

The purpose of this study was to examine the variability between the speech produced by two age groups of adult females, a young adult group and a geriatric group. The 25 women in each group phonated three productions of the vowel /a/ for 5 s at three effort levels—maximum, comfortable, and minimum. Recordings of these productions were digitized and analyzed for mean intensity and intensity distribution. The women also repeated a series of CV, VCV, and VC syllables using the consonants /p/, /b/, /t/, /d/, /s/, and /z/ combined with the vowel /a/, in the carrier phrase “Speak_____again.” Intraoral air pressure and the voicing signal were recorded to provide vowel and consonant durations, voice onset times, and peak intraoral air pressure. The F‐max test for homogeniety of variance was used to compare the variability between the two age groups. The older speakers exhibited significantly greater variability than the younger speakers for the dependent variables, peak intraoral air pressure, consonant duration, vowel duration, voice onset time, and the minimum effort level of speech intensity. The greater variability of production exhibited by the older speakers could be a factor in the perception of older speakers.

Peak intraoral air pressure in [p] as a function of F0 in Chinese.

The study explores the differences in peak intraoral air pressure in voiceless unaspirated bilabial stop consonant [p] in a CV syllable in which V is produced with different tones. Native speakers of four Chinese languages that have different tonal systems participated in the investigation. The results show that there is a positive correlation between the peak intraoral air pressure in [p] and the onset Fovalue of the tone that occurs on the following vocalic element. The results are discussed in terms of possible physiological explanations, such as the use of a higher subglottal pressure to produce a higher fundamental frequency.

Aerodynamic and palatographic characteristics of the early stages of speech adaptation to a dental appliance

Subjects were recorded speaking with a dental appliance, similar to an orthodontic retainer, which had 4 mm of thickness in the alveolar region. Comparisons were made between initial attempts to speak with such an appliance and speech after two weeks of adaptation. Data consisted of oral air flow, peak intraoral pressure, dynamic electropalatography and the microphone signal. Focus was on /s/ in VCV contexts. The very first utterance showed deviations in timing of airflow characteristics in relation to devoicing, which were rapidly corrected. Aerodynamic and palatographic evidence of smaller articulatory constriction for /s/ was also seen initially, but this feature was not adjusted adequately in the early speech attempts.

Segmental gestures at the laryngeal level in whispered speech: evidence from an aerodynamic study.

Peak intraoral air pressure and flow were measured simultaneously for the syllables /pa/ and /ba/ in two speaking conditions (syllable repetitions, and in carrier phrases) and in two phonation modes (normal phonation and whisper). Results indicated that 1) the difference between the intraoral air pressure for /p/ and /b/ was statistically significant in normal phonation, but not in whisper, 2) the difference in peak flow for /p/ and /b/ was statistically significant in both normal phonation and whisper, and 3) the pressure and flow data were unaffected by speaking conditions. These data, plus a subsequent analysis of intraoral pressure slopes, are taken to indicate that the voiceless and voiced members of a stop-cognate pair are produced in whisper with unique laryngeal gestures.

Relation of peak intraoral air pressure to tone

Much attention has been paid to the differences in peak intraoral air pressure between voiced and voiceless stop consonants. The present study, however, explores the differences in peak intraoral air pressure in voiceless unaspirated bilabial stop consonant [p] in a CV syllable where V is produced with different tones. Native speakers of three Chinese dialects which have different tonal systems participated in the investigation. The results show that there is a positive correlation between the peak intraoral air pressure in [p] and the onset F0 value of the tone that occurs on the following vocalic element. The results are discussed in terms of possible physiological explanations, such as the use of a higher subglottal pressure to produce a higher F0. [Research supported by NSF.]

The influence of utterance length upon bilabial closure duration of selected deaf children

Measurements were made of intraoral air pressure associated with bilabial closure durations of VCV syllables in sentence-like frames of increasing length for nine deaf and nine matched normal hearing children. Results demonstrated significantly longer absolute closure durations at all utterance lengths for the deaf, but with the same relative decrease in closure durations with increases in utterance length for both groups. The deaf children showed lower peak intraoral air pressure values with more variability than the normal children. In addition, the deaf children had longer air-pressure pulse durations than did the normals. Clinical application of these findings to speech management are discussed.