Acoustic rhinometric measurements of changes in velar positioning.

Acoustic rhinometry as a means to detect changes in velar position was examined in this study. Videofluoroscopic recordings were made of two normal speakers maintaining velopharyngeal open and velopharyngeal closed (silent /f/) targets. Simultaneous acoustic rhinometric recordings were made during the production of each stimulus. Determinations of changes in velar positioning during the closed samples were made from fluoroscopic recordings and compared to nasal cavity-nasopharynx changes detected by rhinometry. The excellent agreement between the measures from the two procedures (less than 1 cm) indicates that acoustic rhinometry is capable of detecting changes in velar positioning during "silent" speech. Implications for assessment and future research are discussed.

Integrated endoscopic/photodetector evaluation of velopharyngeal function.

A new integrated videoendoscopic/photodetection system, including an endoscope with an internal instrument channel used for photodetection, was applied to the evaluation of velopharyngeal closure in a subject with marginal velopharyngeal insufficiency (VPI) and in a subject with no speech disorder. Acoustic and aerodynamic speech assessments were used to establish the severity of velopharyngeal impairment in the marginal VPI patient. A light-out condition was used to establish the photodetector criterion for closure. The new system was effective for providing detailed phonetic assessment of velopharyngeal closure. Variations in degree of closure during select oral and nasal consonant productions were identified in the VPI subject but not in the normal speaking subject. The data show that important details of velopharyngeal insufficiency can be identified using the integrated endoscopic/photodetection system.

Videoendoscopy and photodetection: linearity of a new integrated system.

Simultaneous videoendoscopy and photodetection has potential for improving the assessment of changes in velopharyngeal (VP) movements and closure over time during speech. The purpose of this project was to examine the linearity of a new system, including a pediatric bronchoscope with an internal instrument channel through which the photodetector fiber was positioned. The results led to the conclusion that the response of the new system was linear. However, further examination indicated that system positioning variables had important effects on the overall level of photodetector light detection. These observations confirm the importance of monitoring and controlling the position of the endoscope-photodetector apparatus in the nasopharynx when using the system to evaluate velopharyngeal movement and closure for speech.

Relative values of various standardized passages in the nasometric assessment of patients with velopharyngeal impairment.

A series of 155 patients referred for evaluation at the UNC Craniofacial Center was studied to compare nasometric performance data obtained from the Rainbow Passage to information provided when subjects read two other standardized passages (Zoo Passage and Nasal Sentences). Nasometric findings obtained using the three reading passages were compared to aerodynamic estimates of velopharyngeal area and nasal cross-sectional area as well as clinical judgments of hypernasality and hyponasality. The results suggest that the Rainbow Passage does not provide clinically relevant information that cannot be obtained using the other speech samples studied.

A study of nasometric values for normal nasal resonance.

It was the purpose of this study to obtain nasalance values for a large number of normal adult subjects speaking a variety of dialects of English. The Nasometer was used to measure the amount of nasal acoustic energy in the speech of 148 normal adults from four geographical regions of North America. Means and standard deviations for the nasalance and deviation scores are presented for each of three different reading passages. The Mid-Atlantic speakers were found to have significantly higher nasalance scores on all three reading passages. In addition, the female subjects had significantly higher nasalance scores on the Nasal Sentences. These differences are discussed with regard to potential reasons for their existence and implications for understanding velopharyngeal function in normal and abnormal speakers.

Communication problems associated with cleft palate and related disorders. Annotated bibliography.

The books in this annotated bibliography were selected because of the general nature of the information that they provide. Most of these books contain bibliographies that include references of a more technical nature should the reader desire such information. These books are available at most university libraries. Additional information can be obtained from brochures and fact sheets published by the Cleft Palate Foundation (1218 Grandview Avenue, Pittsburgh, PA 15211). These publications were prepared primarily for patients and parents, but can provide useful information to professionals who typically do not work with patients with cleft palate and craniofacial anomalies.

Using simultaneous nasometry and standard audio recordings to detect the acoustic onsets and offsets of speech.

Simultaneously collected nasometric and standard audio recording data were compared to determine the extent to which the acoustic onsets and offsets of speech could be determined from Nasometric signals. Three male and 2 female subjects produced six repetitions of 12 utterances that were initiated and terminated by vowels and consonants of differing phonetic features. The onset of Nasometer output typically followed output from the standard audio recording system by an average of 29 ms (SD = 36.1 ms). A greater temporal discrepancy was observed for signal offsets (mean Nasometer lag = 100 ms; SD = 83.3 ms). Large differences between the two instruments seemed due to differences in their overall sensitivities. The results suggest that the Nasometer may be of limited value in determining the acoustic onsets and offsets of speech. The Nasometer was not designed to sense the acoustic events studied here, and the current results have no bearing whatsoever on the validity of this instrument in providing information concerning nasal resonance.

Nasometric and phototransductive measurements of reaction times among normal adult speakers.

The temporal relationship among laryngeal, velopharyngeal, and labial activity was investigated by studying the reaction times of eight normal adults. Four female and four male subjects sustained production of the nasal consonant /m/ until a computer-driven imperative tone was presented at which time they were required to say /pi/ as quickly as possible. This task was repeated 30 times for each subject. The offset of voicing at the end of the /m/ and the onset of bilabial plosive release were monitored using a commercially available Nasometer. The onset of velopharyngeal (V-P) movement toward closure and the attainment of closure were monitored using a photodetector system. Across 240 responses, the average latencies were: 146 ms for initiation of V-P movement toward closure, 224 ms for voicing offset, 280 ms for onset of V-P closure and 317 ms for onset of plosive release. The significance of these findings is discussed with respect to speech motor control and the clinical evaluation of patients with velopharyngeal impairments.

A comparison of photodetector and endoscopic evaluations of velopharyngeal function.

Simultaneous videoendoscopic and photodetection analyses were made of specific onset and offset times of velopharyngeal opening and closing in two normal speaking subjects. Both procedures were found to have acceptable measurement repeatability and to agree with each other when used to determine movement changes. It is felt that when used together, these techniques contribute to improved understanding of velopharyngeal activity during speech.

Comparison of cineradiographic and photodetection techniques for assessing velopharyngeal function during speech.

This study investigated the extent to which high-speed lateral-view cineradiography and a photodetector system described by Dalston (1982) provided comparable information concerning velopharyngeal activity. We observed the production of isolated utterances and running speech for 2 subjects in three contexts. A comparison was made between the times at which the velopharyngeal port was observed by each method to begin opening, reach maximal opening, begin closing, and initially attain closure. The photodetector system was found to be sensitive to changes in velar position observed by cineradiography. The correlation between the magnitude of photodetector output and the magnitude of velar displacement from the posterior pharyngeal wall was .89 for Subject 1 and .78 for Subject 2. The lack of a perfect relation between the output of the photodetector device and movements of the velum observed by cineradiography was not unexpected given the two-dimensional limitation of lateral cineradiography and the complexity of events associated with changing port size. The significance of these findings is discussed with respect to the potential research and clinical uses of this photodetector system.

A comparison of speech sound durations in three syndromes of aphasia.

This study compared the durations of selected vowels and consonants produced by three groups of aphasics and a normal control group in confrontation naming and single-word repetition tasks. There were seven aphasic subjects in each of the syndromes of Broca's, Wernicke's, amnesic, and conduction aphasia, in addition to a group of seven normal subjects. Wide-band spectrograms were used to measure speech sound durations. Analysis of group data revealed no significant differences in the durations of vowels or consonants across the four subject groups. In addition, there were no differences in speech sound durations for the confrontation naming versus repetition tasks. When two speech-language pathologists listened to tape recordings of all subjects performing the two tasks, they judged the speech of two Broca's aphasics as being labored, while the speech of the remaining subjects was not judged as labored. Clinical judgments of labored speech appeared to correspond to acoustical measurements of speech sound duration, as the two Broca's aphasics judged to be labored displayed longer durations than those subjects who were not judged as labored. The increase in duration was particularly marked for vowels and for sounds in polysyllabic words. The results are discussed in relation to current descriptions of the articulatory characteristics of Broca's aphasics. Clinical implications are also addressed.

Nasality and velopharyngeal function in five hearing impaired adults.

Cineradiographic observations of velopharyngeal functioning and listener judgments of hypernasality were compared for five hearing impaired adults. All of the hearing impaired speakers were perceived to have speech characterized by excessive nasality, while only two of the subjects exhibited any velopharyngeal opening. The relationships between the perception of excessive nasality and variables other than the physiology of the velopharyngeal mechanism are discussed.

A cineradiographic and electromyographic investigation of velar positioning in non-nasal speech.

Simultaneous cineradiographic and electromyographic analyses were made of the speech of three male and three female normal speaking adults. Each subject produced a series of symmetrical non-nasal CVC syllables embedded in a carrier phrase in a normal manner and also at increased rate and effort levels. A model of velar control was formulated and tested in relationship to changes in velar height resulting from forces provided by tongue positioning and contraction of levator veli palatini, palatoglossus, and palatopharyngeus muscles. Two patterns of levator activity were observed in the six subjects. Palatopharyngeus activity appeared to be important in producing adjustments in exact velar position when the velum was in a elevated state. Palatoglossus activity appeared to be related to elevation of the posterior portion of the tongue. The time differences between changes in muscle activity and velar positioning were determined. The results provide additional normative data regarding velar activity and serve to illustrate the need to view the velum as a complex mechanical system.

A radiographic investigation of velar positioning in hearing-impaired young adults.

Listener judgments of the presence and severity of hypernasality were made of speech samples from 25 hearing-impaired young adults. These judgments were compared to the results of manometric testing, cephalometric analyses of velar positioning, and analyses of nasal air emission, nasal rustle, and glottal stops. Only two examples of velopharyngeal opening were observed in the radiographic analysis. Also, those subjects judged to be hypernasal failed to exhibit behavior on the other clinical measurements, which was consistent with expectations based on observations of hypernasality in the oral-facial cleft-palate population. The results of this study illustrate the need for continued research into the anatomical and physiological attributes of the perceived hypernasality in the hearing impaired. Also, the remedial consequences of these findings are discussed.