Biomedical subjects

R Mayo

Publications and source records attributed to R Mayo.

24 records · Page 2Linked to original sources

PubMed1993

Hypernasality in the presence of "adequate" velopharyngeal closure.

In some instances, hypernasality occurs despite an instrumental assessment of "adequate" velopharyngeal closure. The pressure-flow technique was used to assess the timing characteristics associated with velopharyngeal closure in 11 such subjects. The group's performance was compared to the aerodynamic characteristics of two other subject groups. One was comprised of 13 cleft palate subjects with adequate closure and normal nasal resonance, while the second group consisted of 16 noncleft subjects who also manifested normal speech. The data indicate that there are several unique timing features that differentiate the hypernasal but "adequate" group from the two control groups. These include a delay of about 50 ms in achieving closure, a longer interval of nasal emission, and a shorter duration of actual closure. Hypernasality seems to be associated with the actual time the velopharyngeal mechanism is open, rather than the volume of air escaping from the nasal chamber.

Airway Resistance↗

PubMed1993

Perceptual assessment of resonance distortion in unoperated clefts of the secondary palate.

The purpose of this study was to examine the frequency with which five speech-language pathologists made judgments of hypernasality during the clinical assessment of young children with unoperated and repaired clefts of the secondary palate. Among the 293 nonsyndromic patients with secondary palate clefts included in this study, 219 were between 1 and 2 years of age. Of those, 83 had undergone primary palatoplasty whereas 136 had not. The remaining 74 children were between the ages of 4 and 5 years and presented with repaired secondary palatal clefts. The results showed that the clinicians were unable or unwilling to assess hypernasality in 31% of the 1 to 2 year old children with unoperated clefts. The same clinicians failed to evaluate oral-nasal resonance balance in only 12% of the children in the 1- to 2-year age group who had undergone palate repair. Only 1 of the 74 older children (1.4%) was not evaluated for hypernasality. Possible explanations for these findings are presented and discussed.

Child Language↗

PubMed1992

Controlling changes in vocal tract resistance.

There is some evidence that speech aerodynamics follows the rules of a regulating system. The purpose of the present study was to assess how the speech system manages perturbations that produce "errors" within the system. Three experimental approaches were used to evaluate the physiological responses to an imposed change in airway resistance. The first involved subjects with varying degrees of velopharyngeal inadequacy. The second and third approaches involved noncleft subjects whose airway was perturbed by bleed valves and bite blocks during consonant productions. The pressure-flow technique was used to measure aerodynamic variables associated with the production of test consonants. The results of this study provide additional evidence that the speech system actively responds to perturbations in ways that tend to minimize a change in consonant speech pressures. The degree of success in stabilizing pressures appears to reflect the capability of the system to use whatever articulatory and respiratory responses are available.

Adult↗

PubMed1990

Effects of short-term endotracheal intubation on vocal function.

Transient voice change associated with endotracheal intubation has generally been attributed to vocal fold trauma. To assess the role of altered vocal fold function in transient voice change, a study was designed to evaluate the audioacoustic, endoscopic, and laryngostroboscopic characteristics of the postintubation voice. Vocal function of 10 patients undergoing short-term outpatient surgical procedures using general anesthesia and endotracheal intubation were studied preoperatively and postoperatively. A second group of 10 patients that did not have surgery or general anesthesia was used as an age-matched control. Fundamental frequency, frequency perturbation, electroglottography, endoscopy (including laryngeal stroboscopy), and subjective speech analysis by experienced listeners were used to assess vocal function. No consistent differences in fundamental frequency were observed, although patient-to-patient variation was marked. Statistically significant increases in cycle-to-cycle fundamental frequency variation (jitter) were found postoperatively in the majority of the postintubation patients (P less than 0.05). Electroglottography, laryngeal endoscopy, and stroboscopic laryngoscopy did not demonstrate consistent changes in glottic mucosal function. Listener judgments characterized the postintubation voice change by decreased intensity, increased roughness, and lowered affect without consistent changes in pitch. The perception of decreased affect in the voices (characterized by reduction in pitch variation, vocal stress, and increases in pause times) was a strong perceptual marker for change in the post-intubation voice. Objective measures of laryngeal function suggest that the glottic contribution to postintubation voice change is minimal and that this dysphonia is probably multifactorial.

Adolescent↗

PubMedDate not supplied

The use of the Mayo Clinic system for differential diagnosis of dysarthria.

The purpose of this study was to determine clinicians' attitudes toward the Darley, Aronson, and Brown (1969a, 1969b; 1975a) method of classification for differential diagnostic of dysarthria. A national telephone survey was conducted of 100 speech-language pathologists involved in the assessment and treatment of patients with dysarthria. Clinicians were questioned about their use of differential diagnosis as part of their service delivery to persons with dysarthria. Questions also focused on clinicians' perceptions of the helpfulness and difficulties of differential diagnosis. Results indicated that most clinicians use the Darley et al. (1969a, 1969b; 1975a) classification system for the differential diagnosis of dysarthria, stating that it is helpful in the design of a treatment protocol. A trend toward decreased perceived difficulty of differential diagnosis with increased years of work experience was observed. The clinical and academic training implications of these findings are discussed.

Data Collection↗

PubMedDate not supplied

The influence of acoustic and perceptual factors on perceived hypernasality in the vowel.

The purpose of this study was to examine the influence of acoustic and perceptual factors of speech on listeners' perceived hypernasality in the vowel [i]. The isolated syllable [pi] produced by 22 children with hypernasal speech and 6 noncleft children was rated by 10 listeners. These speech samples were then divided into two groups: (1) the samples (n = 14) that received inconsistent ratings from each listener or variable ratings among listeners (i.e., unreliable ratings) and (2) the samples (n = 14) that received consistent ratings from each listener and similar ratings among listeners (i.e., reliable ratings). These results suggest that the severity of hypernasality was easy to rate in some speech samples and not in others. Voice quality deviation and a particular type of spectral change that related to the severity of hypernasality could be factors that influence perceived hypernasality.

Adolescent↗