Journal of speech and hearing research最新文献

The purpose of this study was to document changes in aerodynamic and glottographic aspects of vocal function in patients with Parkinson disease who received two forms of high effort treatment. Previous reports (Ramig, Countryman, Thompson, & Horii, 1995) have documented increased sound pressure level (SPL) following treatment that trained phonation and respiration (Lee Silverman Voice Treatment: LSVT), but not for treatment that trained respiration only (R). In order to examine the mechanisms underlying these differences, measures of maximum flow declination rate (MFDR) and estimated subglottal pressure (Psub) were made before and after treatment. A measure of relative vocal fold adduction (EGGW) was made from the electroglottographic signal during sustained vowel phonation. Sound pressure level data from syllable repetition, sustained vowel phonation, reading, and monologue tasks were also analyzed to allow a more detailed understanding of treatment-related change in several contexts. Consistent with increases in SPL, significant increases in MFDR, estimated Psub, and EGGW were measured posttreatment in patients who received the LSVT. Similar changes were not observed following R treatment. These findings suggest that the combination of increased vocal fold adduction and subglottal pressure is a key in generating posttreatment increases in vocal intensity in idiopathic Parkinson disease (IPD).

This study describes the manipulation and synthesis of LPC parameters to edit incorrectly produced utterances. In particular, it shows that formant frequencies can be manipulated to produce a consistent and reliable change in perception. It also demonstrates that this method can be used to produce quality synthesis of high-pitched voices.

This paper presents the results of a controlled trial of child stuttering treatment. The aim of the study was, first, to compare the effectiveness of three viable treatments, and, second, to compare these three treatments to a no-treatment control composed of children who stuttered of a similar age and sex ratio who were on treatment waiting lists. The three treatments investigated included intensive smooth speech, intensive electromyography feedback, and home-based smooth speech. The children/adolescents were assessed across three speaking contexts on measures of percentage syllables stuttered (% SS) and syllables spoken per minute (SPM) and outcomes were assessed 12 months later. Repeated measures analyses of variance demonstrated significant differences between the control group and all three treatment groups across time on conversations in the clinic, on the telephone, and at home (although home measures were not taken for the intensive smooth speech group). Although the controls' stuttering did not change across time, the treatment groups' stuttering was decreased to very low levels posttreatment (less than 1% syllables stuttered on average), with mean improvement in stuttering frequency of at least 85% to 90% across all assessment contexts. Stuttering did not increase significantly up to 3 months and one year posttreatment in the experimental groups, although levels did rise across time (less than 3% syllables stuttered on average). Speech naturalness results showed increasing naturalness across time as rated by the clinician and parent. This was not the case for the controls. The children were also less anxious across time following treatment. The results suggest that all three treatments for children aged 9-14 who stutter were very successful in the long term for over 70% of the group, though the EMG feedback and home-based treatments were superior when percentages falling below a cutoff point (2%SS) were used to discriminate between groups. Implications for child/adolescent treatment in the community are discussed. Long-term outcomes will be assessed up to 5 years after the treatment.

This research determined frequency importance functions (FIFs) for words, sentences, and continuous discourse under comparable conditions so that contextual effects of speech could be isolated. A male talker recorded 616 monosyllabic words, 176 meaningful sentences, and 44 continuous discourse (CD) passages. Twenty-four participants with normal hearing made intelligibility estimates of the CD passages and sentences and identified words in each of 44 low- and high-pass filtering and signal-to-noise ratio conditions. Plots of frequency versus percent of contributed intelligibility, or the FIFs, revealed that the frequency band that contributes the most to intelligibility is centered near 2000 Hz for all three types of speech. The results show a single peak in the importance function and a statistical analysis of the shape of the FIF (with kurtosis the pertinent measure) shows that there is a significant difference in the shape of the FIF based upon speech type. The data were also calculated into near-octave bands with similar results. The statistical analysis presented provides the basis for a test of the hypothesis: The degree of context or message redundancy is related to the relative importance of the frequency bands. The findings potentially have clinical as well as predictive implications.

A case study is presented of a 5-year-old boy who was classified as preschool handicapped and was assessed as having a specific expressive language impairment with verbal apraxia. Chromosomal studies revealed a de novo (new) balanced translocation between first and second chromosomes. Results of the neurological, speech/language, cognitive, and play evaluations revealed a child with a severe expressive speech-language deficit but good nonverbal cognitive and communicative skills. The hypothesis of a relationship between a chromosomal translocation and speech/language disorders is explored.

Speech samples from groups of White, African American, and Hispanic kindergarten-age children were compared on measures of mean speaking fundamental frequency (F(zero)), maximum and minimum speaking F(zero), pitch sigma, and speaking range (in semitones). Results indicate that there are significant differences between racial groups on measures of mean speaking F(zero) and speaking range. In particular, the Hispanic children were observed to have increased mean speaking F(zero)S in comparison with the African American children and reduced speaking ranges as compared to both African American and White racial groups. Results indicate that the speech-language pathologist must exercise discretion when assessing the speaking F(zero) characteristics (particularly mean speaking F(zero) and speaking range) of children from different racial groups.

This study examined temporal parameters of speech in subjects with apraxia of speech, conduction aphasia, and normal speech. They were asked to repeat target words in a carrier phrase 10 times. Acoustic analyses involved measurement of stop gap duration, voice onset time, vowel nucleus duration, and consonant-vowel (CV) duration. Speakers with apraxia of speech had longer and more variable stop gap, vowel, and CV durations than did subjects with aphasia or normal speech. Speakers with conduction aphasia had longer vowel durations and CV durations than subjects with normal speech. Also, subjects with apraxia of speech showed greater token-to-token variability than the other subject groups. The variability shown by subjects with apraxia of speech was significantly correlated with perceptual judgments of their speech. The significance of these results is discussed in the context of motoric and phonological explanations for apraxia of speech and conduction aphasia.

Criteria for identification of children as specifically language impaired (SLI) vary greatly among clinicians and researchers. Standardized psychometric discrepancy criteria are more restrictive and perhaps less sensitive to language impairment than is clinical judgment based on a child's language performance in naturalistic contexts. This paper examines (a) differences in groups of preschool children clinically diagnosed as SLI who were and were not identified as SLI through standard psychometric discrepancy criteria, and (b) the validity of quantitative measures of mean length of utterance (MLU), syntax, and pragmatics derived from a spontaneous language sample as criteria for discriminating clinically diagnosed preschoolers from normally developing preschoolers. Spontaneous language data indicated that children clinically identified as SLI produced a significantly higher percentage of errors in spontaneous speech than normal children whether they met psychometric discrepancy criteria or not. Logistic regression analysis indicated that a combination of MLU, percent structural errors, and chronological age was the optimal subset of variables useful for predicting a clinical diagnosis of SLI. This combined criterion captured a larger proportion of the clinically identified SLI children than even the best psychometric discrepancy criteria.

Electrically evoked whole nerve action potentials (EAP) have been recorded from 20 ineraid cochlear implant users in response to bipolar and/or monopolar electrical stimulation of the cochlea. EAP growth functions and refractory recovery functions were obtained for a variety of different stimulating conditions. Where possible, parallel psychophysical experiments were conducted that measured the just detectable increment in stimulus current level (JND), forward-masking functions, and detection thresholds for a range of different stimuli. Variations in EAP threshold, slope of the EAP growth function, and the rate of recovery of the EAP from the refractory state were observed both across subjects for a given place and by mode of stimulation (bipolar versus monopolar), as well as across electrodes within a subject. A poor correlation between slope of the EAP growth functions and current JNDs was obtained. However, good correlations were observed between EAP threshold and psychophysical detection threshold and between the EAP refractory recovery functions and the psychophysical forward-masking functions. Our interpretation of these findings is that these particular physiological measures are related to the excitability of the auditory nerve to electrical stimulation and further that these measures are related to performance of cochlear implant patients on listening tasks. Consequently, such information may prove to be useful in adjusting the stimulation parameters of the cochlear implant speech processor in order to maximize an individual's performance with the device.