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Biomedical subjects

J D Amerman

Publications and source records attributed to J D Amerman.

12 recordsLinked to original sources
PubMed1993

A maximum-force-dependent protocol for assessing labial force control.

A protocol based on target levels, referenced to maximum voluntary closing force (MVCF), was used to assess static force control in the perioral musculature. Twenty normal-speaking subjects were instructed to produce rapid and accurate isometric force trajectories to end-point target levels and maintain force on-target for 5 sec while viewing a computer monitor. Each lip was assessed on a number of quantitative force control measures at 10, 20, 50, and 75% of MCVF. The 10% and 20% target levels were included so that static force control could be evaluated within the presumed physiological operating range for normal speech. Results of the target-level scaling procedure revealed that the upper lip was more stable in controlling force at all four targets. The use of MVCF-based target scaling is discussed in relation to absolute nonscaled force analysis methods applied to the perioral motor system.

Adult↗
PubMed1990

Auditory impressions of the speech of normal elderly adults.

Forty speech-language pathologists listened to randomised recorded samples of the 'Grandfather Passage' read aloud by 10 normal elderly male adults, 10 normal young male adults and 6 dysarthric subjects. The speech samples were rated according to the 38 dimensions devised by Darley and colleagues for the study of the dysarthrias. The ratings of the speech of the older adults fell significantly further from 'normal' on a seven-point continuum than those given to the young adults on nine of the dimensions. The most apparent young/old differences involved laryngeal dimensions. Ratings for the normal geriatric subjects resembled those of the dysarthric groups in some respects. Several instances of misclassification of the normal elderly individuals as 'dysarthric' were also observed.

Adult↗
PubMed1987

Perception of oral diadochokinetic performances in elderly adults.

Twenty speech-language pathologists judged the adequacy of oral diadochokinetic performances by ten normal young adult speakers, ten normal geriatric speakers, and four dysarthric speakers (foils) for the purpose of investigating age-related changes in speech. Listeners rated each speaker according to 11 perceptual dimensions. Significant differences in ratings were found among the three subject groups for 10 of the 11 perceptual dimensions. The performances of elderly normal adult speakers were rated farther from the "normal" endpoint of a seven-point continuum than those of the young normal adults. The listeners also reported lesser degrees of confidence in their ratings of the geriatrics in comparison with both young adult and dysarthric groups. Perceptual characteristics associated with oral diadochokinetic performance appear to be altered with advanced age. Further analysis of clinicians' judgments suggest support for Ryan and Burk's (1974) proposal that the speech of aged adults may fall at the "mild end of a dysarthric continuum." Results emphasized the need for development of clinical standards of speech normality for the geriatric population.

Adult↗
PubMed1979

Age and the decoding of coarticulatory cues.

Thirty-two subjects between the ages of 60 and 80 years listened to tape-recorded voiceless stop + vowel syllables and subsyllabic segments systematically isolated from the syllables by electronic gating. This procedure allowed examination of the ability of older adults to perceive the acoustic effects of coarticulation. Comparison of the performances of subjects in the older age groups with previous data concerning four year olds, 11 year olds, and young adults (Oarnell and Amerman, 1978) revealed a close resemblance between the performance of four year olds and older adults in the proportion of correct syllable identifications, consistency of responses and substitution preferences. On all of these measures, the responses of these two age groups differed significantly from those of the 11 year olds and young adults. The results suggest a reduction in decoding precision for these coarticulatory cues as a function of the aging process.

Adult↗
PubMed1978

Maturational influences on perception of coarticulatory effects.

Three experimental groups consisting of ten four-year-olds, ten 11-year-olds, and ten adults were presented with tape-recorded voiceless stop + vowel syllables and subsyllabic segments isolated from the syllables by electronic gating. Subjects were instructed to identify each syllable. Comparisons of the performances of subjects in the three age groups permitted description of maturational influences on the ability to utilize coarticulatory cues in speech perception. The responses of the four-year-olds indicated that they were able to process coarticulatory information for the identification of consonants and vowels from subsyllabic segments. However, their ability to utilize these cues were more limited than that of 11-year-olds and adults. The four-year-old children experienced particular difficulty in the use of aperiodic information. The relative distribution of perceptual cues throughout the portions of the CV syllables was similar for all age groups. The overall phoneme identification accuracy levels of the 11-year-olds appeared to be established at an adult accuracy level. However, differences among all three age groups in regard to consistency of responses, markedness of substitution error preferences, and magnitude of the influence of acoustic stimulus duration on response accuracy suggest that strategies for estimation of phoneme identity may undergo further modification beyond the 11-year-old level before attaining the characteristics of the adult decoding process.

Adult↗
PubMed1977

Subjective evaluation of articulatory effort.

Thirty-two adult speakers repeated pairs of CV syllables, each embedded in a carrier phrase, and designated the consonant member of the pair they believed required more articulatory effort. The task was performed under three speaking conditions (1) normal conversational speech, (2) whispered speech, and (3) pantomimed speech. Voicing and fricative manner of production appeared to be related to judgments of greater articulatory effort. Highly consistent responses across the three speaking conditions suggest other psychological factors to which subjects respond during conditions of normal as well as subvocal modes of speaking. Analyses yielded significant correlations between articulatory effort responses and current data concerning children's phonological acquisition, children's phoneme substitution patterns, and frequency of occurrence of consonants in conversational English.

Adult↗
PubMedDate not supplied

The staggered spondaic word test: a normative investigation of older adults.

The use of the Staggered Spondaic Word Test (SSW) J. Katz et al., J. Speech Hear. Disord. 33, 132--146, for measurement of central auditory ability in adults beyond the age of 60 years is presently limited by the lack of an adequate normative data base by which to differentiate typical and atypical response patterns obtained from elderly subjects. To provide a description of SSW performances for older age groups, the SSW was administered to 41 subjects ranging in age from 60 to 79 years. Average word discrimination scores for the experimental population were within normal limits. The subjects evidenced a decrease in response accuracy and an increase in response variability relative to previously reported SSW results obtained from younger subjects. Nonsignificant correlations between age and SSW scores suggest minimal change in those central auditory functions assessed by the SSW test for subjects between the ages of 60 and 79 years. The need for stricter control over cognitive awareness and capability in the design of experiments that involve elderly subjects is discussed.

Age Factors↗
PubMedDate not supplied

The use of visual stimuli during auditory assessment.

Two groups of male subjects beyond 50 years of age were given audiometric tasks with and without visual stimulation to determine if visual stimuli changed auditory perception. The first group consisted of 10 subjects with normal auditory acuity; the second, 10 with sensorineural hearing losses greater than 30 decibels. The rate of presentation of the visual stimuli, consisting of photographic slides of various subjects, was determined in experiment I of the study. The subjects, while viewing the slides at their own rate, took an audiotry speech discrimination test. Advisedly they changed the slides at a speed which they felt facilitated attention while performing the auditory task. The mean rate of slide-changing behavior was used as the "optimum" visual stimulation rate in experiment II, which was designed to explore the interaction of the bisensory presentation of stimuli. Bekesy tracings and Rush Hughes recordings were administered without and with visual stimuli, the latter presented at the mean rate of slide changes found in experiment I. Analysis of data indicated that (1) no statistically significant difference exists between visual and nonvisual conditions during speech discrimination and Bekesy testing; and (2) subjects did not believe that visual stimuli as presented in this study helped them to listen more effectively. The experimenter concluded that the various auditory stimuli encountered in the auditory test situation may actually be a deterrent to boredom because of the variety of tasks required in a testing situation.

Aged↗