Intraoral Air Research Articles

The formaldehyde inspiration by the child patient, dentist, and dental assistant during formocresol pulpotomy

Although using Buckley's Solution of formocresol (FC) in pulpotomy procedures is becoming less common in pediatric dentistry. This study measured concentrations of formaldehyde (FA) evaporated during fixing and investigated safe procedures for FC pulpotomy. Methods: Ten measurements were taken for each of the conditions described below. Locations measured for each condition were 1) at a position equivalent to the patient, 2) at a position equivalent to the dentist, and 3) at a position equivalent to the assistant dentist. Condition 1 used no peripheral equipment. Condition 2 used an intraoral air evacuator, Condition 3 used extraoral air evacuators, Condition 4 used both extraoral and intraoral air evacuators. At the patient's FA levels were 0.414 ppm during Condition 1, 0.158 ppm during Condition 2, 0.252 ppm during Condition 3, and 0.091 ppm during Condition 4. FA levels at the dentist were 0.115 ppm during Condition 1, 0.042 ppm during Condition 2, 0.081 ppm during Condition 3, and 0.028 ppm during Condition 4. FA levels at the dental assistant were 0.067 ppm during Condition 1, 0.038 during Condition 2, 0.059 ppm during Condition 3, and 0.025 ppm during Condition 4. Exposure concentrations of FA during FC pulpotomy might have using of an extraoral, intraoral air evacuator during FC pulpotomy reduces formaldehyde exposure to patient, dentist, and dental assistant.

Phonetically grounded phonology and sound change: The case of Tswana labial plosives

A widely held assumption in phonology is that phonology should be phonetically grounded. Under a strict version of this view, productive phonological processes that counter phonetic naturalness should not be possible. Traditional grammars of Tswana describe it as having a productive process of post-nasal devoicing of voiced plosives (/mb/→[mp]), counter to phonetic expectations. The vocal fold settings during the nasal should promote, not inhibit, voicing in a following consonant. Leakage through the velic valve during the initial part of the post-nasal oral closure should inhibit buildup of intra-oral air pressure and hence promote voicing. The unexpectedness of the Tswana pattern leads to questioning the accuracy and reliability of the traditional descriptions of this language. In this paper, we report an acoustic study of 12 Tswana speakers, showing that there is evidence that at least some speakers have an active, productive process of post-nasal devoicing. However, our data also show evidence that this phonetically unnatural system is unstable, and is in fact in the process of changing towards a more natural system. We consider the relevance of these results for views about the relationship between phonetics and phonology, and for theories of language change.

Nasoendoscopy of velopharynx before and during diagnostic therapy.

Nasoendoscopy is an important tool for assessing velopharyngeal function. The purpose of this study was to analyze velar and pharyngeal wall movement and velopharyngeal gap during nasoendoscopic evaluation of the velopharynx before and during diagnostic therapy. Nasoendoscopic recordings of 10 children with operated cleft lip and palate were analyzed according to the International Working Group Guidelines. Ratings of movement of velum and pharyngeal walls, and size, location and shape of gaps were analyzed by 3 speech-language pathologists (SLPs). Imaging was obtained during repetitions of the syllable/pa/during a single nasoendoscopic evaluation: (a) before diagnostic therapy, and (b) after the children were instructed to impound and increase intraoral air pressure (diagnostic therapy). Once the patients impounded and directed air pressure orally, the displacement of the velum, right, left and posterior pharyngeal walls increased 40, 70, 80, and 10%, respectively. Statistical significance for displacement was found only for right and left lateral pharyngeal walls. Reduction in gap size was observed for 30% of the patients and other 40% of the gaps disappeared. Changes in gap size were found to be statistically significant between the two conditions. In nasoendoscopic assessment, the full potential of velopharyngeal displacement may not be completely elicited when the patient is asked only to repeat a speech stimulus. Optimization of information can be done with the use of diagnostic therapy's strategies to manipulate VP function. Assuring the participation of the SLP to conduct diagnostic therapy is essential for management of velopharyngeal dysfunction.

Glottal‐opening and airflow pattern during production of voiceless fricatives: a new non‐invasive instrumentation

In the production of voiceless fricatives, the airflow passing through the vocal tract is controlled by reciprocal open‐close patterns of the glottal and oral constriction. In order to observe such coordinated patterns, the authors have developed a combined method using a non‐invasive (external‐lighting and sensing) photoglottographic (ePGG) technique and a pressure‐difference airflow mask. The former technique has the advantage of no restriction of phonetic environments (improvement from the standard PGG) and can be further combined with instrumentation of intraoral air pressure and/or of articulatory movements. Our PGG‐airflow data are examined to address a question: It has been known that the glottis opens always wider for word‐initial fricatives than for word‐medial ones despite no obvious difference in acoustic and physiological requirements. It will be discussed whether the degrees of glottal opening during a fricative co‐vary with other aerodynamic and articulatory controls in CVCV utterances with V = nonclose vowels.

On Intraoral Air Pressure and Air Flow Rate of the Japanese Dental Plosives /t,d/ Spoken by Korean Learners

On Intraoral Air Pressure and Air Flow Rate of the Japanese Dental Plosives /t,d/ Spoken by Korean Learners

Treatment of velopharyngeal closure for speech: Discussion and implications for management.

Abstract The velopharyngeal closure mechanism acts as a valve to separate the oral and nasal cavities during speech and swallowing. Velopharyngeal closure deficits are generally identified by the speech-language pathologist and corrected through surgery or speech prosthetics. However, there is a small subset of clients who may benefit from treatments using task specific muscle rehabilitation procedures. This review article addresses the following topics: structure/function relationships of velopharyngeal closure, motor programming of velopharyngeal closure, aims and findings of various types of muscle treatment programs, discussion and rationale of successful muscle treatments, and guidelines for utilizing muscle treatment for the management of clients with velopharyngeal closure deficits. Keywords: Velopharyngeal closure, muscle treatment, nasal emission, hypernasality. Introduction Velopharyngeal closure is the neurophysiologic act of partitioning the oral cavity from the nasal cavity during speech and nonspeech activities. Thompson and Hixon (1979) characterize the velopharyngeal closure mechanism as a valve whose actions act to separate the oral and nasal cavities. Moon and Kuehn (1996) describe the mechanism for speech as an articulator that must operate according to rules of neuromotor programming, and whose activity must be synchronized with the actions of other articulators to attain perceptually acceptable speech. McWilliams, Morris, and Shelton (1984, 1990) indicate that velopharyngeal closure for speech consists of velar movement and contact with the lateral and posterior pharyngeal walls. The velum moves in an upward and backward direction to articulate with the pharyngeal walls. Normal speakers exhibit differential patterns of muscle activity of the velum, lateral pharyngeal walls and posterior pharyngeal wall (Iglesias, Kuehn, & Morris, 1980; Shprintzen, Lencione, McCall & Skolnick, 1974; Zwitman, Sonderman, & Ward, 1974). That is, they achieve closure but the articulators contribute in different ways depending on the speaker. Velopharyngeal closure for speech allows a speaker to generate sufficient air pressure and flow for the production of pressure consonants and also permits the production of voiced sounds without hypernasal resonance. Speakers who are unable to achieve velopharyngeal closure or who exhibit faulty timing of closure often demonstrate problems with speech production and such problems manifest in articulation and resonance disorders (Kuehn, 1979; Morris, 1992; Warren, Dalston, & Mayo, 1993). Articulation problems are normally found with the plosive, fricative and affricate sound categories, since they require the generation of high intraoral air pressure (McWilliams et al., 1990; Peterson-Falzone, Hardin-Jones,& Karnell, 2001; Shelton, Hahn, & Morris, 1968; Shelton, Morris, & McWilliams, 1973). These pressure sounds, may be produced with nasal emission, or the client may use compensatory substitutions in place of the pressure sounds. Audible nasal emission is the auditory perception or air passing through the nose during the production of a pressure sound. The speaker may produce the sound at the correct point of articulation, but nasal emission accompanies the production. Compensatory errors are sounds that are used in place of pressure sounds and generally produced at a more posterior point of articulation than the intended sound. For instance, one of the most frequent compensatory errors utilized by speakers with cleft palate is the glottal stop. It is produced by bringing the vocal folds together to create a complete constriction and then releasing the built-up air pressure created by the lungs. Resonance is the product of the transfer function of the laryngeal sound source (Peterson-Falzone et al., 2006). The vocal tract acts as a filter to selectively modify in different ways the complex laryngeal tone that is created by the vibration of the vocal folds. …

Resistência laríngea em indivíduos com fechamento velofaríngeo marginal

OBJETIVO: Verificar se pacientes com disfunção velofaríngea marginal modificam a resistência laríngea como uma estratégia para alcançar o fechamento velofaríngeo completo durante a fala. MÉTODOS: Foram avaliados 19 pacientes com fissura de palato operada, de ambos os sexos com idade entre 12 e 47 anos, com fechamento velofaríngeo marginal e 18 indivíduos sem fissura (grupo controle), de ambos os sexos, com idade entre 14 e 35 anos. A resistência laríngea (R), pressão aérea intra-oral (Po) e fluxo oro-nasal (Vº) foram obtidos por meio de avaliação aerodinâmica utilizando-se o sistema PERCI-SARS durante a produção da sílaba /pa/, com e sem a oclusão das narinas. RESULTADOS: Os valores médios de resistência laríngea (R), pressão aérea intra-oral (Po) e fluxo oro-nasal (Vº), no grupo com fechamento velofaríngeo marginal, foram de, respectivamente, 34,8±10,8 cmH2O/L/seg, 4,8±1,4 cmH2O, 144,8±34,0 mL/s, sem a oclusão das narinas e de 34,0±14,3 cmH2O/L/seg, 4,8±1,1 cmH2O, 150,9±38,7 mL/s com a oclusão das narinas. No grupo controle, os valores médios foram 39,2±13,4 cmH2O/L/seg, 4,8±0,8 cmH2O, 133,9±50,2 mL/s, respectivamente para as mesmas variáveis. Não houve diferença estatisticamente significante (p<0,05) entre os valores médios de resistência laríngea (R), pressão aérea intra-oral (Po) e fluxo oro-nasal (Vº) dos grupos estudados. CONCLUSÃO: Esses resultados mostraram que os pacientes com fechamento velofaríngeo marginal estudados não modificaram a resistência laríngea.

Speech and Voice Physiology of Children Who Are Hard of Hearing

The purpose of this investigation was to examine the nature and frequency of deviant speech and voice physiology in children who are hard of hearing (HH). Ten HH children (age, 5 to 15 yrs) participated. Their hearing losses ranged in severity from moderate to severe. The following speech/voice physiological measures were examined: frequency of occurrence of negative intraoral air pressure (-Po), magnitude of Po, phonatory air flow, nasal air flow, voice onset time (VOT), and fundamental frequency (F0). Findings were compared with data previously collected from 56 children with normal hearing and 7 children with cochlear implants (Higgins, McCleary, Carney, & Schulte, 2003). Five of the 10 HH children exhibited deviant speech/voice behaviors. Only one showed deviancy on more than one measure. In addition, 8 HH children had some borderline-deviant speech behavior. The frequency and degree of speech/voice deviancy for the children in the present study was far less than what we previously had observed for children who underwent cochlear implantation after 5 yrs of age (Higgins et al., 2003). This was the case even for a child with a cochlear implant from our earlier study who eventually achieved speech perception scores that were as good as or better than some of the HH children in the present investigation. Deviant speech/voice physiology occurs to a limited extent for some HH children. Of the measures that we examined, those related to vocal fold tension and vocal fold articulation appeared to be most sensitive to the effects of diminished auditory input and feedback that occurs for HH children. Data from this and other studies suggest that abnormally high F0 occurs for about 20% of HH children and may be associated with poor speech perception skills. Future studies should examine whether earlier implantation can help deaf children to produce speech that is at least as normal as that of HH children.

Effect of intraoral air pressure on the release of an alveolar stop closure

The effect of air pressure on the release of an alveolar stop consonant closure is simulated with a 2-D finite-element model of the front part of the midsagittal tongue in the vocal tract. Active movement of the tongue is estimated from x-ray microbeam recordings, and intraoral air pressure is also applied to the surface of the tongue as an external force. Air flow in the vocal tract is then coupled to the tongue movement by representing the upper tongue surface as part of the flow boundary. At release, the upward movement of the tongue tip due to the decrease in air pressure introduces an oscillation at the release trajectory of the supraglottal constriction. This oscillation is realized in a quasiarticulatory speech synthesizer HLsyn and causes the appearance of a plateau in the time course of the output airflow. This hesitation in tongue tip movement results in an increase in the duration of the frication noise by about 10 ms, consistent with acoustic data on the stop burst. The simulation shows how the mechanical properties of the tongue and the intraoral air pressure buildup can influence the duration of the frication noise. [Supported by Grant NIDCD DC00075 from NIH.]

Intraoral Air Pressure Discrimination under Conditions of Experimental Velopharyngeal Insufficiency

This study assessed a single subject's ability to detect the difference limen (DLs) for his self-generated intraoral air pressure while his oral and nasal cavities were experimentally coupled. The subject, a 46-year-old man, uses a speech bulb prosthesis to cover an unrepaired cleft of his hard and soft palates. The subject's oral and nasal cavities were experimentally coupled by drilling different size holes through the speech-bulb component of the prosthesis to approximate conditions of velopharyngeal insufficiency. There were four hole-size conditions (10, 15, 20, and 30 mm(2)), a no-prosthesis condition, and pre- and postbaseline conditions with the prosthesis intact. The subject blew into a tube connected to a pressure transducer and was presented with a series of paired pressure loads. The first pressure load of each pair was the referent (1, 3, or 5 cm H(2)O), and the second was a preselected comparator load of a different amount. The subject blew into the tube with sufficient force to center the voltage meter's needle at the zero mark. The subject then reported whether the second pressure load required more, less, or equal breath pressure, compared with the referent pressure load of that pair. Size of the hole coupling the oral/nasal cavities did not significantly affect the subject's difference limen. Experimental coupling of the oral/nasal cavities did not affect this subject's ability to detect differences in his self-generated intraoral air pressure.

An electronic database of Norwegian speech sounds: clinical aspects

The Electronic database of Norwegian speech sounds under development at the University of Oslo is intended to be a resource for phonetic research and practice. Beside its theoretical contribution as a research tool and as a basis for cross-linguistic comparison, one of the primary goals is for the database to be a tool that can assist in the treatment of speech and language impaired subjects with articulatory disorders. A number of registration techniques are used: the main techniques are simultaneous EPG and EMA recordings, registering oral passive and active articulation, respectively. This is complemented by measurements of vocal fold activity, intraoral air pressure, and nasal and oral emission of airflow. With the addition of the acoustic picture, provided by spectrography, all major aspects of speech production are covered and may be displayed in an explicit manner.

Single motor unit activity in levator veli palatini during speech and nonspeech tasks.

This article assesses the control of velar movement by relating observed recruitment patterns of single motor unit activity in levator veli palatini observed during speech and nonspeech tasks in a single subject to intraoral pressure demands. Electromyographic activity was recorded from a single motor unit in levator veli palatini during repetitions of "Say (----) again" with selected consonant-vowel-consonant and consonant-vowel syllables, sustained high pressure consonants, and blowing tasks. Single motor unit firing characteristics (e.g., frequency of occurrence, firing frequency) were related to intraoral air pressures recorded during the sustained consonant and blowing tasks. Levator single motor unit activity was always present during the /s/ in "say" and the first and second /s/ in /sis/. Activity was observed less consistently during the production of the /s/ in /sus/, the /p/ in /p Lambda/, and the /g/ in "again." Single motor unit firing frequency ranged from 16.1 Hz to 22 Hz during phrase productions. Recruitment was observed during sustained productions of high-pressure consonants when intraoral pressures exceeded 15 cm H(2)O. Increases in intraoral air pressure were associated with 25% to 85% increases in single motor unit firing frequencies. During nonspeech blowing tasks, single motor unit activity was observed when intraoral air pressure exceeded approximately 12 cm H(2)O. Increases in intraoral air pressure were again associated with increased single motor unit firing rates. Results showed evidence of both preprogrammed and feedback-controlled responses by levator veli palatini to changes in task intraoral pressure demands.

Single Motor Unit Activity in Levator Veli Palatini During Speech and Nonspeech Tasks

Abstract Objective: This article assesses the control of velar movement by relating observed recruitment patterns of single motor unit activity in levator veli palatini observed during speech and nonspeech tasks in a single subject to intraoral pressure demands. Methods: Electromyographic activity was recorded from a single motor unit in levator veli palatini during repetitions of “Say ____ again” with selected consonant-vowel-consonant and consonant-vowel syllables, sustained high pressure consonants, and blowing tasks. Single motor unit firing characteristics (e.g., frequency of occurrence, firing frequency) were related to intraoral air pressures recorded during the sustained consonant and blowing tasks. Results: Levator single motor unit activity was always present during the /s/ in “say” and the first and second /s/ in /sis/. Activity was observed less consistently during the production of the /s/ in /sus/, the /p/ in /p /, and the /g/ in “again.” Single motor unit firing frequency ranged from 16.1 H...

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

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. 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. 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). 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

Effect of Age, Gender, and Repeated Measures on Intraoral Air Pressure in Normal Adults

The effect of age, gender, and repeated measures on intraoral air pressure (P 0) was examined. Sixty adults comprised of 10 males and 10 females in each of three age groups (i.e., 20–39, 40–59, and 60–83 years) participated. P 0 was assessed during voiceless stop plosive /p/ productions in repeated vowel/consonant syllables. The three medial plosives of a seven-syllable train were averaged to comprise a token. Five tokens were obtained and averaged for each of three trials. Thus each participant contributed 105 syllables and a subsequent three P 0s for analyses. There was no statistically significant difference in P 0 as a function of age or gender ( P > 0.05). These findings support the conception that P 0 remains stable throughout adulthood and is not dependent on gender. Differences in repeated measures of P 0 attained statistical significance ( P = 0.03), however the mean differences between trials (0.23 cm H 20) were negligible and deemed to be clinically insignificant. Thus, across a short sampling session, P 0 is a relatively stable measurement and does not change as a function of age or gender.

Intraoral Air Pressure Discrimination under Conditions of Partial and Complete Resistance

This study assessed a sample of normal-speaking individuals’ ability to discriminate differences in their self-generated intraoral air pressures. Two conditions were employed: (1) open tube in which subjects had to sustain an expiratory breath stream to maintain the target pressure, and (2) closed tube in which there was complete resistance to the subjects’ breath stream. Analysis of variance revealed no significant difference (p > 0.05) in subjects’ ability to discriminate differences in their self-generated intraoral air pressure as a function of open or closed tube conditions. However, subjects’ discrimination scores significantly increased (p < 0.05) as the standard pressure was increased.

Articulatory changes with short-term deactivation of the cochlear implants of two prelingually deafened children.

The purpose of this investigation was to determine how suddenly diminished auditory feedback affects articulatory behaviors for prelingually deafened children with cochlear implants (CIs). Two 6-yr-old children served as participants. Considering their level of hearing impairment, one child had above average speech perception and production skills while the other child had exceptionally good speech perception and production abilities. Baseline data were collected four times over the course of 2 days with the children wearing their CIs. For three additional days, data were collected while the children wore their CIs (ON condition) and then again after their CIs had been deactivated for 1 hr (OFF condition). Variables assessed included amount of jaw opening, F1, F2, nasal air flow, voice onset time (VOT), voicing duration, and the magnitude and duration of intraoral air pressure (Po). Findings were related to each other and to previously reported phonatory findings from the same two children (Higgins, McCleary, & Schulte, 1999) to determine whether changes in articulatory variables in the OFF condition were consistent with a direct effect of diminished auditory feedback or an indirect influence of suprasegmental parameters. Both children exhibited consistent and significant changes in articulatory parameters in the absence of auditory feedback. Such changes occurred more often for the child who had especially proficient speech perception and production skills. Some changes (i.e., reduced Po for [p] and reduced nasal air flow for [m]) appeared related to the influence of suprasegmental parameters, in particular, reduced subglottal air pressure. Other effects (i.e., increased F2 for [a] and reduced VOT for [p]) were suggestive of changes in the children's abilities to maintain appropriate articulatory placements and timing. Finally, a few changes (reduced jaw opening for [i] and increased Po duration for [p]) may have reflected compensatory strategies to maintain correct tongue placement and enhance temporal distinctions in the absence of auditory feedback. Based on the data of our two participants, it appears that some prelingually deafened children with CIs and good speech perception/production skills rely on auditory feedback to maintain articulatory precision. In the absence of auditory feedback, such children may demonstrate changes in articulatory placement and timing. In addition, data from one of our participants are consistent with the idea that some children may be aware that their articulatory control is compromised in the absence of auditory feedback and attempt to compensate by altering articulatory durations or the range of associated articulatory movements.

Use of Visual Feedback to Treat Negative Intraoral Air Pressures of Preschoolers With Cochlear Implants

The primary purpose of this study was to determine if negative intraoral air pressures (−P o ) produced by young deaf children can be treated effectively with visual feedback. We used two forms of visual feedback. One was a display of the P o signal on an oscilloscope, and the other was movement of cellophane streamers placed in front of the children’s mouths. Participants were two 5-year-old boys who had been using cochlear implants (CIs) for less than 6 months. Both children were congenitally deafened and had very limited speech production and perception skills. In addition to frequent usage of −P o , both children exhibited deviant phonatory behaviors, so phonatory goals were incorporated into treatment. The magnitude and direction of P o was monitored, as well as fundamental frequency and electroglottograph cycle width. Data were collected at baseline, before and after treatment sessions, and 7 weeks after termination of treatment. One child responded well to treatment of −P o with both forms of visual feedback, and progress was maintained at follow-up. For the other child, +P o occurred more frequently as the study progressed, and he rarely produced −P o by the end of the investigation. However, because changes were evident in baseline as well as during treatment, it is difficult to attribute his more frequent use of +P o specifically to treatment. The phonation of the two children changed in ways that were consistent with their phonatory goals, although the degree of change was not always significant. Change was more evident for phonatory behaviors that could be shaped with visual feedback. Although both children exhibited some undesirable speech/voice behaviors in response to visual feedback, there was no evidence of long-lasting mislearning. Although our data are limited, it appears that treatment of −P o can be efficacious for some young children with CIs, even those with very poor speech perception and speech production skills. Further, treatment of −P o can be incorporated effectively with other speech production goals.

Aerodynamic and Acoustic Parameters in CO2 Laser Posterior Transverse Cordotomy for Bilateral Vocal Fold Paralysis

The aim of this prospective study was to analyse airway improvement and acoustic and aerodynamic parameters after CO2 laser posterior transverse cordotomy (LPTC) in bilateral vocal fold paralysis (BVFP). Four patients (2 males, 2 females) were recorded pre- and post-operatively at 1, 3, 6, 12 and 24 months. Forced inspiratory volume during the first second (FIV), vital capacity, peakflow, and forced expiratory volume during the first second (FEV) were measured with the Gould II spirometer. Acoustic frequency features (average fundamental frequency, standard deviation, jitter, shimmer and harmonic-to-noise ratio) and speech duration parameters (maximum phonation time, number of words read per minute, and number of words per breath) were measured. Aerodynamic parameters were measured with the Aerophone II. Three tasks were completed. Pneumo-phonatory parameters in ?maximum sustained phonation? and in ?comfortable phonation?, and laryngeal aerodynamic parameters (intraoral air pressure, oral airflow and sound pressure level) were measured non-invasively. Glottal resistance and vocal efficiency were calculated. FIV increased significantly after LPTC (p=0.01). Postoperatively, frequency features were undetectable by standard commercialized algorithms. Acoustic and aerodynamic parameters improved in the measures obtained at the 6th postoperative month. These results were stable 2 years postoperatively in all cases. We conclude that laryngeal aerodynamic parameters can be used objectively to follow patients longitudinally after LPTC.

Do Airstream Mechanisms Influence Tongue Movement Paths?

Velar consonants often show an elliptical pattern of tongue movement in symmetrical vowel contexts, but the forces responsible for this remain unclear. We here consider the role of overpressure (increased intraoral air pressure) behind the constriction by examining how movement patterns are modified when speakers change from an egressive to ingressive airstream. Tongue movement and respiratory data were obtained from 3 speakers. The two airstream conditions were additionally combined with two levels of speech volume. The results showed consistent reductions in forward tongue movement during consonant closure in the ingressive conditions. Thus, overpressure behind the constriction may partly determine preferred movement patterns, but it cannot be the only influence since forward movement during closure is usually reduced but not eliminated in ingressive speech.