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Objective: This study examined the relation between nasal port area, nasalance, and perceptual ratings of nasality for three English corner vowels, /i/, /u/, and /a/., Design: Samples were simulated using a computational model that allowed for exact control of nasal port size and direct measures of nasalance. Perceptual ratings were obtained using a paired stimulus presentation., Participants: Four experienced listeners., Main Outcome Measures: Nasalance and perceptual ratings of nasality., Results: Findings show that perceptual ratings of nasality and nasalance increased for samples generated with nasal port areas up to and including 0.16 cm(2) but plateaued in samples generated with larger nasal port areas. No vowel differences were noted for perceptual ratings., Conclusions: This work extends previously published work by including nasal port areas representative of those reported in the literature for clinical populations. Continued work using samples with varied phonetic context and varying suprasegmental and temporal characteristics are needed.

Objective: The purpose of this study was to examine the relation of perceptual ratings of nasality by experienced listeners, measures of nasalance, and the size of the nasal port opening for three simulated English corner vowels, /i/, /u/, and /a/., Design: Samples were generated using a computational model that allowed for exact control of nasal port size and a direct measure of nasalance. Perceptual ratings were obtained using a paired-stimulus presentation., Participants: Five experienced listeners., Main Outcome Measures: Measures of nasalance and perceptual nasality ratings., Results: Differences in nasalance and perceptual ratings of nasality were noted among the three vowels, with values being greater for the high vowels /i/ and /u/ compared to the low vowel /a/. Listeners detected nasality for the high and low vowels simulated with nasal port areas of 0.01 and 0.15 cm(2), respectively. Correlations between ratings of nasality and nasalance were high for all three vowels., Conclusions: Results of the present study show a high correlation between ratings of nasality and measures of nasalance for nasal port areas ranging from 0 to 0.5 cm(2). The correlations were based on sustained vowel samples. The restricted speech sample limits generalization of the findings to clinical data; however, the results are a demonstration of the usefulness of modeling to understand the perceptual phenomena of nasality.

Many adolescents and adults with Down syndrome have reduced speech intelligibility. Reasons for this reduction may relate to differences in anatomy and physiology, both of which are important for creating an intelligible speech signal. The purpose of this study was to document acoustic vowel space and articulatory working space for two adult speakers with Down syndrome who had reduced speech intelligibility (mean = 56% based on single words). Articulatory data for the tongue were collected using a real-time flesh-point tracking method (i.e. X-ray microbeam). Results show smaller F1?F2 acoustic vowel space area for both speakers with Down syndrome compared with the control speakers. Reduced articulatory working space area and slower movement speed were also found for three of the four tongue points analysed. Although generalizations are limited by the small number of participants, findings warrant further investigation of the underlying articulatory characteristics of speech production for individuals with Down syndrome.

This study investigates the importance of fundamental frequency (F0) as a perceptual cue for identification of vowel targets produced by speakers with Parkinson's disease (PD). It has been suggested in the literature that F0 is a redundant cue for vowel identification in highly intelligible speech. For speakers with dysarthria who are having difficulty with segmental and suprasegmental aspects of production which result in ambiguous or conflicting cues in the acoustic signal, F0 may have increased perceptual importance for accurate identification of vowel targets. In the present study, F0 contours for single-word targets produced in sentence level material by 20 speakers with PD and 20 control speakers were synthetically modified in several different ways (i.e., flattened and enhanced). Listener identification of vowel targets across the F0 conditions was recorded. The accuracy of vowel identification for the control group was not affected by the flattening of the F0 contour. For the speakers with PD, however, modification of the F0 contour (flattening or enhancing) affected the accuracy with which listeners identified certain vowels. Differences in vowel identification were found primarily for the front vowels /I, epsilon, ae/ along a high-low continuum., (Copyright 2006 S. Karger AG, Basel.)

Unlabelled: This study examined patterns of lung volume use in speakers with Parkinson disease (PD) during an extemporaneous speaking task. The performance of a control group was also examined. Behaviors described are based on acoustic, kinematic and linguistic measures. Group differences were found in breath group duration, lung volume initiation, and lung volume termination measures. Speakers in the control group alternated between a longer and shorter breath groups. With starting lung volumes being higher for the longer breath groups and lower for shorter breath groups. Speech production was terminated before reaching tidal end expiratory level. This pattern was also seen in 4 of 7 speakers with PD. The remaining 3 PD speakers initiated speech at low starting lung volumes and continued speaking below EEL. This subgroup of PD speakers ended breath groups at agrammatical boundaries, whereas control speakers ended at appropriate grammatical boundaries., Learning Outcomes: As a result of participating in this exercise, the reader will (1) be able to describe the patterns of lung volume use in speakers with Parkinson disease and compare them with those employed by control speakers; and (2) obtain information about the influence of speaking task on speech breathing.

During early speech development, the velopharyngeal mechanism may play a major role in the rapid expansion of a child's repertoire of speech sounds. Results of a longitudinal study suggest that, during spontaneous speech, velopharyngeal closure is largely complete by the age of 19 months. There is evidence, however, of differences in the consistency of velopharyngeal closure between sound categories. This finding has implications for early speech assessment and intervention decisions in clinical populations. [ABSTRACT FROM AUTHOR]

Purpose: Darley, Aronson, and Brown (1969a, 1969b) detailed methods and results of auditory-perceptual assessment for speakers with dysarthrias of varying etiology. They reported adequate listener reliability for use of the rating system as a tool for differential diagnosis, but several more recent studies have raised concerns about listener reliability using this approach. Method: In the present study, the authors examined intrarater and interrater agreement for perceptual ratings of 47 speakers with various dysarthria types by 2 listener groups (inexperienced and experienced). The entire set of perceptual features proposed by Darley et al. was rated based on a 40-s conversational speech sample. Results: No differences in levels of agreement were found between the listener groups. Agreement was within 1 scale value or better for 67% of the pairwise comparisons. Levels of agreement were lower when the average rating fell in the mid-range of the scale compared with samples that had an average rating near either of the scale endpoints; agreement was above chance level. No significant differences in agreement were found between the perceptual features. Discussion: The levels of listener agreement that were found indicate that auditory-perceptual ratings show promise during clinical assessment for identifying salient features of dysarthria for speakers with various etiologies. [ABSTRACT FROM AUTHOR]

Purpose: To examine the influence of visual information on speech intelligibility for a group of speakers with dysarthria associated with Parkinson's disease. Method: Eight speakers with Parkinson's disease and dysarthria were recorded while they read sentences. Speakers performed a concurrent manual task to facilitate typical speech production. Twenty listeners (10 experienced and 10 inexperienced) transcribed sentences while watching and listening to videotapes of the speakers (auditory-visual mode) and while only listening to the speakers (auditory-only mode). Results: Significant main effects were found for both presentation mode and speaker. Auditory-visual scores were significantly higher than auditory-only scores for the 3 speakers with the lowest intelligibility scores. No significant difference was found between the 2 listener groups. Conclusions: The findings suggest that clinicians should consider both auditory-visual and auditory-only intelligibility measures in speakers with Parkinson's disease to determine the most effective strategies aimed at evaluation and treatment of speech intelligibility decrements. [ABSTRACT FROM AUTHOR]

This study was designed to explore the relationship between perception of a high-low vowel contrast and its acoustic correlates in tokens produced by persons with motor speech disorders. An intelligibility test designed by Kent, Weismer, Kent, and Rosenbek (1989a) groups target and error words in minimal-pair contrasts. This format allows for construction of phonetic error profiles based on listener responses, thus allowing for a direct comparison of the acoustic characteristics of vowels perceived as the intended target with those heard as something other than the target. The high-low vowel contrast was found to be a consistent error across clinical groups and therefore was selected for acoustic analysis. The contrast was expected to have well-defined acoustic measures or correlates, derived from the literature, that directly relate to a listeners' responses for that token. These measures include the difference between the second and first formant frequency (F2-F1), the difference between F1 and the fundamental frequency (F0), and vowel duration. Results showed that the acoustic characteristics of tongue-height errors were not clearly differentiated from the acoustic characteristics of targets. Rather, the acoustic characteristics of errors often looked like noisy (nonprototypical) versions of the targets. Results are discussed in terms of the test from which the errors were derived and within the framework of speech perception theory. [ABSTRACT FROM AUTHOR]

Dysprosody was studied in four groups of male subjects: subjects with amyotrophic lateral sclerosis (ALS) and mild intelligibility impairment, subjects with ALS and a more severe intelligibility loss, subjects with cerebellar disease, and neurologically normal controls. Dysprosody was assessed with perceptual ratings and acoustic measures pertaining to the regulation of duration, f[sub 0], and intensity within tone units of conversational samples. Intelligibility reduction and prosodic disturbance were not necessarily equally impaired in all subjects, and it is concluded that these are complementary indices of severity of dysarthria. Compared to the neurologically normal control group, the clinical groups tended to decrease the overall duration of tone units, produce fewer words in a tone unit, and use smaller variations in f[sub 0] . Recommendations are offered for the assessement of. [ABSTRACT FROM AUTHOR]