Aerodynamic and temporal aspects of velopharyngeal function in normal speakers

Task-Dependent Velopharyngeal Timing in Singers with Classical Training

OBJECTIVE

This study examined velopharyngeal (VP) timing characteristics during singing and speaking tasks among singers with varying degrees of classical training.

METHODS

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

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: 200 ms, total duration of the /mp/ sequence: 212 ms) than for speaking (OP pulse duration: 228 ms, total duration of the /mp/ sequence: 238 ms). The pitch had a significant main effect on OP pulse duration, with C5 (207 ms) significantly shorter than C4 (221 ms). Loudness was found to have no significant main effects on any of the VP timing variables.

CONCLUSIONS

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.

Examining Relationships Between GRBAS Ratings and Acoustic, Aerodynamic and Patient-Reported Voice Measures in Adults With Voice Disorders

OBJECTIVE

To determine if auditory-perceptual voice ratings performed using the GRBAS scale correlate with acoustic and aerodynamic measures of voice. A secondary aim was to examine the relationship between GRBAS ratings and patient-reported quality of life scales.

METHODS

GRBAS ratings, acoustic, aerodynamic and patient-reported quality of life ratings were collected from the University of Wisconsin Madison Voice and Swallow Outcomes Database for 508 adults with voice disorders. Acoustic measures included noise to harmonic ratio, jitter%, shimmer%, highest fundamental frequency (F0) of vocal range, lowest F0 of vocal range, maximum phonation time and dysphonia severity index. Aerodynamic measures included phonation threshold pressure, subglottal pressure, mean transglottal airflow and laryngeal airway resistance. Patient-reported quality of life measures included the Vocal Handicap Index (VHI) and Glottal Function Index (GFI).

RESULTS

GRBAS ratings were significantly correlated with several acoustic and aerodynamic measures, VHI and GFI. The strongest significant correlations for acoustic measures were observed between GRBAS ratings of overall voice quality and perturbation measures (jitter% r = 0.58, shimmer% r = 0.45, noise to harmonic ratio r = 0.36, Dysphonia Severity Index r = -0.56). The strongest significant correlation for aerodynamic voice measures was observed between GRBAS ratings of breathiness and transglottal airflow (r = 0.23), subglottal pressure (r = 0.49), and phonation threshold pressure (r = 0.26). GRBAS ratings were also significantly correlated with both VHI and the GFI scales. R values were higher for the VHI, but remained largely in low range for both scales.

CONCLUSIONS

Although GRBAS ratings were significantly correlated with multiple objective voice and patient related quality of life ratings, r values were low. These findings support the need for multiple voice measures when performing voice evaluations as no single voice measure was highly correlated with voice quality as measured by the GRBAS scale.

Normative Nasalance Values in Vietnamese With Southern Dialect: Vowel and Tone Effects

Purpose The purpose of the current study was to examine normative nasalance values in Vietnamese adult speakers with Southern dialect and to investigate the effects of vowels and tones on nasalance. Previous studies examining nasalance have been mainly conducted with Indo-European languages. Limited information on nasalance is available in tone languages other than Chinese. Furthermore, tone and vowel effects on nasalance scores in tone languages have not been fully examined. Method Nasalance scores of various speech stimuli including passages, syllables, and prolonged vowels were obtained from Vietnamese-speaking adults with Southern dialect (M _age = 23 years) using a nasometer (KayPENTAX 6450). Results The average nasalance scores of Southern Vietnamese adult speakers were 24.16%, 38.17%, and 70.03% for the oral, oral-nasal, and nasal passages, respectively. Southern Vietnamese speakers produced the highest nasalance scores on the vowel /a/, followed by /i/ and /u/. Nasalance scores of stimuli produced with the falling and restricted tone were significantly lower than those produced with the other tones. Conclusions The normative nasalance values of the current study will contribute as a reference index for the Vietnamese language. The effects of vowels and tones can also provide insight into the development of nasalance testing stimuli and for characterizing nasalance values across languages.

The Reliability of Visual Ratings of Velopharyngeal Physiology for Speech

BACKGROUND

Analyze intrarater and interrater reliability for evaluating endoscopic images of velopharyngeal (VP) physiology.

METHOD

Speakers produced 9 speech stimuli representing 4 stimulus types: sustained phonemes, repetitions of "puh," single words, and short phrases. The 37-speaker participants included 16 patients with VP dysfunction and 21 control participants. Five raters independently rated the video images for degree of VP opening, location of opening, and pattern of closure. Outcome measures included intrarater and interrater measures of reliability and the effects of raters and stimulus type on ratings.

RESULTS

Intrarater reliability was acceptable, and ratings were logically consistent. Fixed effects regression coefficients for the patient and the control groups showed that raters were a significant source of variability for degree of opening and pattern of closing. Stimulus type was not a significant source of variation for any metric for the controls, but stimulus type was a significant determinant for degree of opening for patients. The degree of opening was larger for sustained phonemes than for the other speech stimuli. Ratings for degree of opening were most similar for repeated "puh."

CONCLUSIONS

Interrater reliability needs to be improved so that the assessment procedure produces more consistent findings among clinicians, thus strengthening our evidence base for this procedure. Interrater additional research is needed to understand how the stimulus affects ratings of VP physiology, to identify stimuli that yield the most useful clinical information, and to understand how training affects the ratings of VP physiology.

Speech and Language Issues in the Cleft Palate Population: The State of the Art

Objective

State-of-the-art activity demands a look back, a look around, and, importantly, a look into the new millennium. The area of speech and language has been an integral part of cleft palate care from the very beginning. This article reviews the development and progression of our knowledge base over the last several decades in the areas of speech; language; anatomy and physiology of the velopharynx; assessment of velopharyngeal function; and treatment, both behavioral and physical, for velopharyngeal problems.

Method

The clear focus is on the cleft palate condition. However, much of what is reviewed applies to persons with other craniofacial disorders and with other underlying causes of velopharyngeal impairment. A major challenge in the next several years is to sort through speech disorders that have a clear anatomic underpinning, and thus are more amenable to physical management, versus those that may be treated successfully using behavioral approaches. Speech professionals must do a better job of finding and applying ways of treating individuals with less severe velopharyngeal impairment, thus avoiding the need for physical management in these persons or ignoring the speech problem altogether.

Conclusion

Early and aggressive management for speech and language disorders should be conducted. For most individuals born with cleft conditions, a realistic goal should be normal speech and language usage by the time the child reaches the school-age years.

An Acoustic Study of the Temporal Characteristics of Nasalization in Children with and without Cleft Palate

Objective

The purpose of this study was to measure the oral and nasal cavity acoustic energies to determine whether temporal patterns of nasalization differentiate children with and without cleft palate and the extent to which vowel context contributes to these temporal differences.

Design

Nasal onset interval, nasal offset interval, and total nasalization duration measures were obtained from acoustic waveforms, spectrograms, and energy contours acquired using the Computerized Speech Lab (Kay Elemetrics, Lincoln Park, NJ). In addition to absolute temporal values, proportional durations of nasalization were measured to obtain information regarding the relative duration of nasalization.

Participants

Fifteen children with cleft palate exhibiting mild hypernasality and 15 children without cleft palate participated in the study. Children in both groups were between 4 and 7 years of age.

Results

Each of the three absolute measures was significantly different between the two groups of subjects and within the three vowel contexts. Children with cleft palate showed longer temporal characteristics than children without cleft palate in all three absolute measures. The three temporal variables of the high vowel contexts were generally longer than those of low vowel contexts. Regarding proportional measures, nasal offset interval ratio, and total nasalization ratio showed significant differences between the two groups.

Conclusions

Nasalization, as reflected by acoustic signals, showed different timing characteristics between children with cleft palate and without cleft palate and across vowel contexts. This suggests that the duration of nasalization reflecting temporal patterns of the oral-nasal acoustic impedance may have an influence on the perception of hypernasality.

Examining age, sex, and race characteristics of velopharyngeal structures in 4- to 9-year old children using magnetic resonance imaging

Objective

The purpose of this study was to quantify the growth of the various craniofacial and velopharyngeal structures and examine sex and race effects.

Methods

Eight-five healthy children (53 White and 32 Black) with normal velopharyngeal anatomy between 4 and 9 years of age who met the inclusion criteria and successfully completed the MRI scans were included in the study.

Results

Developmental normative mean values for selected craniometric and velopharyngeal variables by race and sex are reported. Cranial variables (face height, nasion to sella, sella to basion, palate height, palate width) and velopharyngeal variables (levator muscle length, angle of origin, sagittal angle, velar length, velar thickness, velar knee to posterior pharyngeal wall, and posterior nasal spine to levator muscle) demonstrated a trend toward a decrease in angle measures and increase in linear measures as age increased (with the exception of PNS to levator muscle). Only hard palate width and levator muscle length showed a significant sex effect. However, two cranial and six velopharyngeal variables showed a significant race effect. The interactions between sex, race, and age were not statistically significant across all variables, with the exception of posterior nasal spine to posterior pharyngeal wall.

Conclusion

Findings established a large age and race-specific normative reference for craniometiric and velopharyngeal variables. Data reveal minimal sexual dimorphism variables used in the present study; however, significant racial effects were observed.

Validity of test stimuli for nasalance measurement in speakers of Jordanian Arabic

OBJECTIVE

The objective of the study was to establish the validity of passages for measuring nasalance of Jordanian speakers of Arabic.

DESIGN

Two Arabic text passages were constructed; the Spring Passage is devoid of nasal consonants and the Home Passage contains both oral and nasal consonants. Nasalance was measured for participants while reciting each passage three times. Perceptual ratings of hypernasality were also obtained for each participant on each passage using a 5-point equal-appearing rating scale.

PARTICIPANTS

Forty-seven children and adults ranging in age between 9 and 26 years participated in the study. Twenty-three participants had no history of communication disorders, and 24 had repaired cleft palate.

RESULTS

Correlation coefficient between ratings of hypernasality and the nasalance scores was significant for the Spring Passage (r = 0.88, p > 0.001) and for the Home Passage (r = 0.78, p > .001). Using cutoff scores of 17% and 36% of nasalance for the Spring and the Home Passages, respectively, and a threshold score of 1.5 for hypernasality, sensitivity for the Spring Passage was 88% and the Home Passage was 78%.

CONCLUSIONS

Results showed the validity of the Spring Passage and the Home Passage in measuring nasalance scores as proved by their high sensitivity and strong correlation with perceptual rating of hypernasality.

Dialectal and gender differences in nasalance for a Mandarin population

The purpose of this study was to determine whether there are dialectal and gender related differences in nasalance of main Mandarin vowels and three sentences in 400 Chinese normal adults. The mean nasalance score difference for dialect and gender was significant (p < .001) in all speech materials. For different dialects, the average nasalance scores show that Chongqing > Beijing > Shanghai > Guangzhou for the nasal sentence, oro-nasal sentence, /a/, /i/ and /u/. In addition, the average nasalance scores of females were higher than those of males for all speech materials in all dialects. The clinical significance of this study can be helpful in making nasalance clinical decisions for Chinese people with cleft palate, hearing disorders and dysarthria with resonance disorders. It also shows the theoretical and socio-cultural features for linguists considering dialects and gender.

Dialectical effects on nasalance: a multicenter, cross-continental study

PURPOSE

This study investigated nasalance in speakers from six different dialectal regions across North America using recent versions of the Nasometer. It was hypothesized that many of the sound changes observed in regional dialects of North American English would have a significant impact on measures of nasalance.

METHOD

Samples of the Zoo Passage, the Rainbow Passage, and the Nasal Sentences were collected from young adult male and female speakers (N=300) from six North American dialectical regions (Midland/Mid-Atlantic; Inland North Canada; Inland North; North Central; South; and Western dialects).

RESULTS

Across the three passage types, effect sizes for dialect were moderate in strength and accounted for approximately 7%-9% of the variation in nasalance. Increased differences in nasalance tended to occur between speakers from distinctly different geographical regions, with the highest nasalance across all passages observed for speakers from the Texas South dialect region.

CONCLUSION

Clinicians and researchers who use perceptual and instrumental measures of speech production should be aware that dialectical and socially acquired speech patterns may influence the acoustic characteristics of speech and may also influence the interpretation of normative expectations and typical versus disordered cutoff scores for instruments such as the Nasometer.

Nasalance scores for typical Irish English-speaking adults

The aim was to establish normative nasalance values for Irish English-speaking adults. Thirty men and 30 women with normal resonance read aloud 16 sentences from the Irish nasality assessment protocol, the Zoo passage, and the Rainbow passage. The speech samples were recorded using the Nasometer II 6400. Results of a mixed between-within subjects ANOVA indicated no significant gender effect on nasalance scores. The speakers showed significantly higher nasalance scores for high-pressure consonant sentences than low-pressure consonant sentences, and for the Rainbow passage than total test sentences. There was no significant difference between high-pressure consonant sentences and the Zoo passage. Compared to previous studies, the Irish young adults had lower nasalance scores than Irish children and than young adults with North American dialects.

Oral Pressure and Nasal Flow on /m/ and /p/ in 3- to 5-Year-Old Children Without Cleft Palate

Objectives : (1) To compare oral pressure and nasal airflow in 3- to 5-year-olds versus older children and adults; (2) to describe stability of these measures in 3- to 5-year-olds at two recording times; and (3) to report participation rates of 3- to 5-year-olds for the aerodynamic protocol. Design : Prospective, nonrandomized, convenience samples in four age groups. Setting : University clinic. Participants : A total of 105 individuals without cleft palate and with normal speech for their age who were 3 to 5 (n  =  45), 7 to 9 (n  =  20), 11 to 13 (n  =  20), or 20 to 30 years old (n  =  20). All had normal nasal resonance and absence of nasally obstructive conditions on the testing day. Main Outcome Measures : Oral pressure and nasal airflow on /p/ and /m/ in syllable series and the word "hamper." Results : Oral pressure was significantly higher on /p/ for 3- to 5-year-olds versus the two oldest groups. Nasal airflow on /p/ occurred infrequently across groups. Oral pressure on /m/ was significantly higher for 3- to 5-year-olds versus adults. Nasal airflow on /m/ increased significantly with age. Oral pressure and nasal flow did not differ at two measurement times for the 3- to 5-year-olds. Of the 3- to 5-year-olds, 88% completed the protocol. Conclusions : Oral pressure decreased on /p/ and nasal airflow increased on /m/ from early childhood into adulthood. Nasal air escape on /p/ occurred rarely for speakers of any age; when it did occur, the magnitude was limited. Most preschool-aged children should be able to complete a velopharyngeal aerodynamic protocol, and measures are stable even for these young speakers.

Perceptions of Audible Nasal Emission in Speakers with Cleft Palate: A Comparative Study of Listener Judgments

Objective

Audible nasal emission is a common speech distortion observed in persons with cleft palate. This study examined the validity and reliability of perceptual judgments of audible nasal emission using interval scaling and magnitude estimation techniques.

Participants

Speech samples were collected from six adolescents with repaired cleft palate, all of whom demonstrated audible nasal emission. A total of 31 adults performed rating tasks in which they judged the severity of audible nasal emission in speech samples.

Measures

Occurrences of audible nasal emission in speech samples were identified using visual and auditory inspection. Using an acoustic modification technique, samples were digitally modified to amplify perceived occurrences of audible nasal emission to create three stimulus conditions. The original recording of the speech samples served as a control condition. The severity of audible nasal emission in the samples was judged by multiple listeners using interval scaling and magnitude estimation without a modulus. Statistical analysis included analysis of variance, regression, and curve-fitting methods.

Results

Magnitude-estimation ratings demonstrated stronger evidence of validity and reliability than interval scaling. A curvilinear relationship was found between the sets of ratings.

Conclusions

The results of this study suggest that audible nasal emission may be a prothetic or ratio-level perceptual continua. Listeners should consider using magnitude estimation or other ratio-based methods for perceptual judgments of audible nasal emission.

Subthalamic nucleus deep brain stimulation changes velopharyngeal control in Parkinson's disease

PURPOSE

Adequate velopharyngeal control is essential for speech, but may be impaired in Parkinson's disease (PD). Bilateral subthalamic nucleus deep brain stimulation (STN DBS) improves limb function in PD, but the effects on velopharyngeal control remain unknown. We tested whether STN DBS would change aerodynamic measures of velopharyngeal control, and whether these changes were correlated with limb function and stimulation settings.

METHODS

Seventeen PD participants with bilateral STN DBS were tested within a morning session after a minimum of 12h since their most recent dose of anti-PD medication. Testing occurred when STN DBS was on, and again 1h after STN DBS was turned off, and included aerodynamic measures during syllable production, and standard neurological ratings of limb function.

RESULTS

We found that PD participants exhibited changes with STN DBS, primarily consistent with increased intraoral pressure (n=7) and increased velopharyngeal closure (n=5). These changes were modestly correlated with measures of limb function, and were correlated with stimulation frequency.

CONCLUSION

Our findings suggest that STN DBS may change velopharyngeal control during syllable production in PD, with greater benefit associated with low frequency stimulation. However, DBS demonstrates a more subtle influence on speech-related velopharyngeal control than limb motor control. This distinction and its underlying mechanisms are important to consider when assessing the impact of STN DBS on PD.

LEARNING OUTCOMES

As a result of this activity, the participant will be able to (1) describe the effects of deep brain stimulation on limb and speech function; (2) describe the effects of deep brain stimulation on velopharyngeal control; and (3) discuss the possible reasons for differences in limb outcomes compared with speech function with deep brain stimulation of the subthalamic nucleus.

Aerodynamic indices of velopharyngeal function in childhood apraxia of speech

Childhood apraxia of speech (CAS) is characterized as a deficit in the motor processes of speech for the volitional control of the articulators, including the velum. One of the many characteristics attributed to children with CAS is intermittent or inconsistent hypernasality. The purpose of this study was to document differences in velopharyngeal function in children diagnosed with CAS from children with typically-developing speech. Pressure-flow techniques were used to estimate the velopharyngeal port size and measure the temporal sequencing of airflow and pressure events associated with production of a nasal + oral plosive sequence in the speech of three children with CAS and three age-matched comparison participants. The results of this pilot study revealed significant differences between the performance of the CAS group and the comparison group in three timing measures of velopharyngeal port closure and velopharyngeal orifice area during speech.

The effect of speaking rate on velopharyngeal function in healthy speakers

The purpose of this study was to assess the effect of speaking rate variation on aerodynamic and acoustic measures of velopharyngeal (VP) function. Twenty-seven healthy adult speakers (14 males, 13 females) participated in the study. The modified pressure-flow method was used to collect aerodynamic data of /m/ and /p/ segments in the word 'hamper' and the utterances 'Mama made some lemon jam' (MMJ) and 'Buy Bobby a puppy' (BBP). SPL was collected simultaneously with aerodynamic data for all utterances. A Nasometer was used to obtain nasalance scores and nasalance distance for MMJ and BBP. Sentences were produced at normal, fast, slow, and slowest speaking rates. The results showed that nasal airflow and VP orifice area were unaffected by speaking rate variations in males and females, whereas intra-oral pressure appeared to decrease as speaking rate slowed for both speaker groups. However, this effect was removed by statistically controlling SPL. Nasalance and nasalance distance (MMJ-BBP) did not change with speaking rate variation. There was a statistical difference between nasalance scores produced by male and female speakers. The results suggested that aerodynamic and acoustic measures of velopharyngeal function are not affected by variation in speaking rate in healthy males and females.

Patterns of oral-nasal balance in normal speakers with and without cleft palate

OBJECTIVE

The aero-acoustic aspects of nasalization that distinguish speakers with velopharyngeal adequacy from those with velopharyngeal inadequacy are well known. Differences in aerodynamic aspects of nasalization also have been demonstrated in normal speakers with cleft palate and their noncleft counterparts. The purpose of this study was to compare the amplitude and temporal patterns of oral-nasal balance in speakers with cleft palate and normal speech to those with normal speech without cleft palate.

PATIENTS AND METHODS

Using the Nasal Accelerometric Vibrational Index technique, the time course and amplitude of oral-nasal balance were studied in 10 children with cleft palate and velopharyngeal adequacy and 10 noncleft controls. The speech sample included syllable, word, and sentence contexts, most of which were devoid of nasal consonants.

RESULTS

The results indicate few differences between the two groups in contexts devoid of nasal consonants. However, significant differences were evident with regard to temporal aspects of oral-nasal balance in a nasal-oral consonant word context.

CONCLUSIONS

Subtle structural-motor differences that may exist between normal speakers with and without cleft palate may be more evident when the spatiotemporal requirements for velar movement become more complex and result in a greater possible combination of oral-nasal impedance ratios.

Velopharyngeal port status during classical singing

PURPOSE

This investigation was undertaken to examine the status of the velopharyngeal (VP) port during classical singing.

METHOD

Using aeromechanical instrumentation, nasal airflow (mL/s), oral pressure (cm H2O), and VP orifice area estimates (cm2) were studied in 10 classically trained sopranos during singing and speaking. Each participant sang and spoke 3 nonsense words-/hampa/, /himpi/, and /humpu/-at 3 loudness levels (loud vs. comfortable vs. soft) and 3 pitches (high vs. comfortable vs. low), using a within-subject experimental design including all possible combinations.

RESULTS

In general, nasal airflow, oral pressure, and VP area estimates were significantly greater for singing as compared to speech, and nasal airflow was observed during non-nasal sounds in all participants. Anticipatory nasal airflow was observed in 9 of 10 participants for singing and speaking and was significantly greater during the first vowel in /hampa/ versus /himpi/ and /humpu/. The effect of vowel height on nasal airflow was also significantly influenced by loudness and pitch.

CONCLUSIONS

The results from this investigation indicate that at least some trained singers experience regular VP opening during classical singing. Vowel height seems to influence this effect. Future research should consider the effects of voice type, gender, experience level, performance ability, and singing style on VP valving in singers.

Speech Aerodynamics and Nasalance in Oral Cancer Patients Treated with Microvascular Transfers

The purpose of the current study was to assess speech aerodynamics and nasal acoustic energy during a follow-up period of 12 months in patients having undergone microvascular free flap reconstruction after tumor ablation from the oral cavity or oropharynx, usually followed by radiotherapy. Velopharyngeal function was assessed in terms of velopharyngeal orifice size by a pressure-flow measurement technique as well as by determining the instrumental correlate of perceived nasality (i.e., nasalance) during speech production. Velopharyngeal closure and nasalance were estimated to be adequate before operation both in oral cavity and oropharyngeal cancer patients. After the operation, at the group level, the oral cavity patients showed adequate velopharyngeal closure and nasalance. In contrast, the postoperative velopharynx orifice size was significantly bigger in the oropharyngeal cancer patients as compared with the oral cavity patients 6 months after operation. However, based on average aerodynamic as well as the nasalance data, the impairment of velopharyngeal function was not regarded clinically significant at the group level in either group of patients. The present treatment protocol served to maintain the prerequisites for normal or close to normal speech physiology.

Longitudinal changes in children's speech and voice physiology after cochlear implantation

OBJECTIVES

The purposes of this investigation were 1) to describe speech/voice physiological characteristics of prelingually deafened children before and after cochlear implantation and determine whether they fall into a range that would be considered deviant, 2) to determine whether selected deviant articulatory and phonatory behaviors of children with cochlear implants persist despite long-term cochlear implant use and continued participation in aural rehabilitation services, and 3) to determine whether further development of deviant articulatory and phonatory behaviors occurs postimplantation.

DESIGN

Seven prelingually deafened children who received cochlear implants after 5 yr of age were followed from shortly before implantation until 5 to 6 yr postimplantation. These children received their early education in a Total Communication environment and used the Nucleus 22-electrode cochlear implant. All of them initially used the MPEAK speech processing strategy, and five of them eventually upgraded to the SPEAK speech processing strategy. Speech/voice physiological measurements that were obtained periodically from the children included intraoral air pressure (P(o)), nasal and phonatory air flow, voice onset time (VOT), and fundamental frequency (F(o)). Data from the deaf children were compared with a database from 56 children with normal hearing to determine when the deaf children exhibited "deviant" speech/voice behaviors. Speech/voice behaviors were considered "deviant" if they never occurred for children with normal hearing or were associated with z-scores that were outside the range of +/-2.0.

RESULTS

The deaf children showed a wide range of deviant speech and voice behaviors both pre- and post-cochlear implant. The most frequently occurring atypical behaviors were use of negative P(o), high P(o) for [b, m], long and short VOT for [p], and high F(o). Some deviant behaviors improved post-cochlear implant. However, deviant behaviors often persisted for several years post-cochlear implant. There was considerable evidence of further development of deviant behaviors post-cochlear implant. All of the deaf children demonstrated deviancy on at least two of our measures at the last data collection interval (5 to 6 yr post-cochlear implant).

CONCLUSIONS

Children who received cochlear implants after 5 yr of age and who were educated in a Total Communication setting showed persistence and further development of deviant speech/voice behaviors for several years post-cochlear implant. Although our findings cannot be generalized to other populations of children with cochlear implants (i.e., those who were implanted earlier, those educated in auditory-oral programs), it seems wisest at the present time not to assume that children's deviant speech/voice behaviors will remit spontaneously with continued cochlear implant use. Our data provide an important comparative database for future investigations of pediatric cochlear implant users who have had shorter periods of auditory deprivation and who have received cochlear implants with more current technological features. Longitudinal Changes in Children's Speech and Voice Physiology after Cochlear Implantation

Temporal characteristics of aerodynamic segments in the speech of children and adults

OBJECTIVES

The primary purpose of this study was to determine the temporal characteristics of aerodynamic segments in the normal speech of children and adults without cleft palate. A secondary objective was to determine the within-speaker variability of the segments.

METHOD

Speakers consisted of 46 children aged 6 to 8 years, 41 older children aged 11 to 12 years, and 41 adults aged 18 to 37 years (total n = 128) who repeated the word "hamper" during continuous utterances. The pressure-flow method was used to determine the duration of six segments of the oral air pressure and nasal airflow pulses associated with the /mp/ sequence. Descriptive statistics, including coefficients of variation (COV), were computed for each segment as a function of age and sex of the speakers. Analysis of variance (ANOVA) procedures were used to determine the effects of age, sex, or both on the temporal variables.

RESULTS

ANOVAs indicated statistically significant main effects (p <.008) for age on five of the six temporal measures and for sex on three of the six measures. Five of the six COVs were also statistically significant for age. There were no statistically significant interactions between speaker age and sex for any measure.

CONCLUSIONS

The results indicate distinct patterns of timing for aerodynamic segments of speech produced by children and adults. Overall, adults exhibited less temporal variability than children. The generally longer and more variable segments produced by children suggest diagnostic and treatment implications relative to speakers with velopharyngeal dysfunction.

Nasal airflow patterns during the velopharyngeal closing phase in speech in children with and without cleft palate

OBJECTIVES

(1) To study the nasal airflow patterns during the velopharyngeal closing phase in speech produced by children with and without cleft palate. (2) To compare the nasal airflow patterns in bilabial, dental, and velar articulation in these children.

DESIGN

Prospective, cross-sectional study of a consecutive series of children with cleft palate referred for routine speech evaluation and controls.

SETTING

Sahlgrenska University Hospital, Göteborg, Sweden.

PARTICIPANTS

Seventeen children with cleft lip and palate or cleft palate only and 22 controls aged 7 and 10 years.

METHOD

Nasal airflow was transduced with a pneumotachograph attached to a nose mask and registered together with the acoustic speech signal. Sentences containing nasal-to-stop combinations in bilabial, dental, and velar articulatory positions were used.

MAIN OUTCOMES MEASURES

The duration from peak to 5% nasal airflow, the maximum flow declination rate, and the nasal airflow at selected points in time during the transition from nasal-to-stop consonants.

RESULTS

In the cleft palate group, duration from peak to 5% nasal airflow was clearly longer than among the controls (p <.0001). The declination of airflow was slower (p <.006) and the rate of nasal airflow at the release of the stop consonant was higher (p <.004) in the cleft palate group. Differences between bilabial versus dental and velar articulation were found in the control group.

CONCLUSION

Studies of the temporal and dynamic characteristics of the nasal airflow variations during speech appear potentially useful for the assessment of velopharyngeal function.

Effects of vowel height and vocal intensity on anticipatory nasal airflow in individuals with normal speech

The purpose of this study was to determine the effects of vowel height and vocal intensity on the magnitude of anticipatory nasal airflow in normal speakers when producing vowel-nasal-vowel (VNV) sequences. Measurements of nasal and oral airflow were obtained from 15 men and 12 women with normal speech during production of the VNV sequences /ini/ and /ana/ at low, medium, and high intensity levels. Ratios of nasal to oral-plus-nasal airflow were calculated for the initial vowel of both utterances at each of the intensity levels. Analysis of variance (ANOVA) procedures indicated a significant main effect of intensity level and a significant vowel-by-sex interaction effect (p < .05) on the airflow ratios. Overall, the airflow ratio was reduced at high as compared to low intensity levels, regardless of sex of the speaker or vowel type. Female speakers exhibited greater airflow ratios during production of /ini/ than during productions of /ana/. Their airflow ratios were also greater during production of /ini/ than were those of male speakers. The results suggest that vocal intensity may affect velopharyngeal (VP) function in an assimilative nasal phonetic context. The results further suggest that anticipatory nasal airflow may be determined by the configuration of the oral cavity to a greater extent in women than in men. Theoretical and clinical implications are discussed.

Pressure-flow characteristics of /m/ and /p/ production in speakers without cleft palate: developmental findings

OBJECTIVE

The purpose of this study was to describe the pressure-flow characteristics of a large sample of speakers without cleft palate ranging in age from early childhood to young adulthood.

METHOD

Speakers consisted of 223 children, teens, and adults without cleft palate categorized into five age groups: 6 through 8 years, 9 through 10, 11 through 12, 13 through 16, and 18 through 37 years. Speakers produced the syllables /mi/, /pi/, and /p/¿/, the word "hamper," and the sentence "Peep into the hamper." The pressure-flow method was used to determine oral air pressure, nasal airflow, and estimates of velopharyngeal (VP) orifice size associated with /ml and /p/ production. Descriptive statistics were computed for each age group and speech sample. Analysis of variance (ANOVA) procedures were used to determine the effects of age, sex, and production level (word versus sentence) on the aerodynamic variables.

RESULTS

ANOVA procedures indicated significant main effects (p < .01) of age on most of the aerodynamic variables during production of /m/ and /p/. No significant main effects or interactions involving sex were found for any variable. Regardless of age, approximately 95% to 99% of the speakers exhibited airtight VP closure during /p/ at syllable level, depending upon the selected nasal airflow criterion. ANOVA procedures also indicated significant main effects of production level (word versus sentence) on each of the aerodynamic variables during the /mp/ sequence. These effects appeared to be related to speaking rate.

CONCLUSIONS

The study suggests that speakers without cleft palate exhibit essentially complete VP closure during production of oral pressure consonants in isolated syllables, and developmental aspects of speech aerodynamics be considered during pressure-flow testing.

Speech sample effects on pressure and flow measures in children with normal or abnormal velopharyngeal function

OBJECTIVE

This study examined the effect of certain test phoneme contexts on oral pressure and nasal flow values in young children with normal velopharyngeal (VP) function. Comparison was made with responses from children with abnormal function. SPEAKERS: Ten children judged to have normal VP function (mean age = 5.2 years) and five children with VP incompetence (mean age = 7.8 years) were evaluated. Both groups were able to produce the speech sample with standard articulatory postures. Subjects were from the local community and a university cleft palate clinic.

DESIGN

Simultaneous oral pressure and nasal flow recordings were obtained from the speakers as they produced /p/ in speech stimuli that varied in terms of test phoneme position in the syllable (releasing and arresting), adjacent vowel height (high, middle, and low), or adjacent consonant characteristics (voicing, placement, and manner). Within-subject differences in pressure and flow were examined to evaluate specific stimulus contrasts in each speaker group.

SETTING

Data were collected in the Speech Physiology Laboratory in the Hearing and Speech Department at the University of Kansas Medical Center.

RESULTS

There were few speech sample effects on oral pressure for children with VP competence. Nasal flow for this group occurred infrequently but was present at least once in 80% of the subjects. The speakers with VP incompetence demonstrated predictable phoneme context effects (higher flow and lower pressure for a nasal context; higher flow for a high vowel context).

CONCLUSION

The finding of no significant stimulus effects for the normal speakers suggests the need for little concern when choosing stimuli for normative study of oral pressure. However, certain stimulus contexts should be considered for data collection if results are to be applied to children with abnormal velopharyngeal function.

Nasal coarticulation in normal speakers: a re-examination of the effects of gender

The purpose of this study was to re-examine the influence of gender on nasal coarticulation in normal speakers. Twenty adult speakers (10 men, 10 women) produced the vowel-nasal-vowel (VNV) sequence /ini/ within a carrier phrase using two stress patterns: (1) with equal stress placed on both syllables, and (2) with contrastive stress placed on the second syllable. A partitioned, circumferentially vented pneumotachograph mask and microphone were used to determine nasal airflow, ratios of nasal to oral-plus-nasal airflow, and sound pressure levels (SPLs) at the midpoints of the first and second vowels of the syllables. Volume ratios of nasal to oral-plus-nasal airflow that reflected the entire duration of the vowels were also obtained. Results indicated that all speakers except 1 woman exhibited nasal airflow at the midpoint of the first vowel when /ini/ was produced with equal stress; all speakers exhibited carryover nasal airflow during the second vowel. During contrastive stress, all speakers except 1 woman and 1 additional man exhibited anticipatory nasal airflow; all speakers exhibited carryover nasal airflow. Analysis of variance (ANOVA) procedures with repeated measures indicated significant main effects of syllable stress (p < 0.001) relative to nasal airflow and ratios of nasal to oral-plus-nasal airflow. Regardless of the gender of the speakers, syllable stress resulted in reduced anticipatory and carryover nasal airflow during the first and second vowels of /ini/, respectively. The results suggest that (a) both men and women adhere to similar patterns of velar articulation, and (b) velopharyngeal closure during the vowel /i/ may be enhanced during stressed syllables. Implications relative to aspects of speech production and clinical practice are discussed.

Temporal characteristics of velopharyngeal function in children

OBJECTIVE

This investigation was designed to examine the performance of children with normal speech on temporal aspects of aerodynamic tasks related to velopharyngeal closure.

DESIGN

The investigation was a descriptive evaluation of variability in aerodynamic features related to velopharyngeal function during multiple repetitions of the word "hamper."

SETTING

Children without speech or velopharyngeal difficulties were seen in an experimental laboratory setting for the evaluation procedures.

PARTICIPANTS

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.).

MAIN OUTCOME MEASURES

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.

RESULTS

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.

CONCLUSIONS

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.

Velopharyngeal closure force and levator veli palatini activation levels in varying phonetic contexts

The purpose of this study was to measure velopharyngeal closure force in varying phonetic contexts for normal men and women subjects. Levator veli palatini muscle activity was measured as well. Place and manner of articulation, voicing, and the effects of consonant sequencing were studied in different vowel contexts. When the data were grouped by sex of subject, no differences were found in absolute values of velopharyngeal closure force for the men versus women subjects. As expected, nonnasal consonants were produced with greater velopharyngeal closure force than nasal consonants. High vowels were produced with greater closure force than low vowels. Closure force was greater for voiceless than for voiced consonants but only for the men and only within /i/ and /u/ contexts. The lingua-dorsal consonant was associated with greater closure force than the lingua-apical consonant but only for the men and only in the high-back vowel environment. Significant differences in closure force were not found between fricatives or stops. A tendency for greater closure force for the fricative consonant was observed when the fricative followed rather than preceded the nasal consonant. Vowel identity had an effect on closure force during consonant production in the men in that closure force was greater for /s/ and /n/ in high versus low vowel contexts. Men exhibited a larger number of significant differences in closure force than did the women. The results suggest that velopharyngeal closure force is not controlled by a single muscle (the levator veli palatini) but that other muscles and mechanical factors are likely contributors.

Velopharyngeal function in young and older adult speakers: evidence from aerodynamic studies

Intraoral air pressure (P0), nasal airflow, and nasal air volume characteristics were determined from 63 adults speakers during production of oral and nasal consonants. The speakers were categorized into two age groups. Young speakers (21 males, 21 females) ranged in age from 18 to 37 years (mean = 24); older speakers (10 males, 11 females) ranged in age from 68 to 83 years (mean = 75). Speakers produced the syllables /pi/ and /si/ and the word "hamper" at self-determined loudness levels during reiterant speech tasks. Results indicated similar velopharyngeal function between young and older adults as reflected by nasal airflow and air volume measures. Older adults, however, exhibited significantly higher levels of P0 than younger adults during production of /p/ in "hamper." In addition (a) male speakers exhibited higher P0 than females during production of /p/ in "hamper," (b) all speakers demonstrated declination of P0 during production of /p/ in "hamper" as a function of word position in the utterance, and (c) male and female speakers exhibited different patterns of nasal air volume during production of "hamper" as a function of word position in the utterance. The intraoral air pressure results suggest differences in respiratory function between young and older speakers. The nasal air volume results suggest a gender specific velopharyngeal declination effect. Implications for velar motor control strategies are discussed.