Journal of speech and hearing research最新文献

Hearing impairment in adults is a prevalent chronic condition, associated with psychosocial and quality-of-life handicaps. Recent investigations have demonstrated that individuals with handicapping hearing impairments do indeed benefit from the rehabilitative services offered by audiologists, with the primary intervention being hearing aid provision. My objective here is to review the experimental research, program evaluation data, and case studies documenting the efficacy of hearing aids, with an emphasis on the functional and communicative benefits accruing from hearing aid use. It is hoped that the information contained herein will provide clinicians with outcome data to share with the hearing impaired, toward the goal of encouraging such individuals to take advantage, at least for a trial period, of one of the many technologies available to assist them to function better in their daily lives.

This investigation was designed to quantify the coordinative organization of mandibular muscles in toddlers during speech and nonspeech behaviors. Seven 15-month-olds were observed during spontaneous production of chewing, sucking, babbling, and speech. Comparison of mandibular coordination across these behaviors revealed that, even for children in the earliest stages of true word production, coordination was quite different from that observed for other behaviors. Production of true words was predominantly characterized by relatively stronger coupling among all mandibular muscles compared with earlier-emerging chewing and sucking. Variegated babbling exhibited stronger coupling than reduplicated babbling, as well as chewing and sucking. The finding of coupled activation among mandibular antagonists during speech paralleled earlier comparisons of adult speech and nonspeech behaviors (Moore, Smith, & Ringel, 1988) and did not support the suggestion that speech coordination emerges from earlier appearing oral motor behaviors.

The primary purpose of this investigation was to examine deaf children's use of negative intraoral air pressures (-Po's) from a physiological and a phonological perspective, with the hope of gathering insight into the strategies these children use to produce speech. A secondary purpose was to compare the effectiveness of two methods of treating these deviant productions. Subjects were four profoundly deaf children, age 6:6-9:2, who used cochlear implants and had demonstrated persistent use of -Po's. Po's were collected during production of CV syllables with initial [p] and [b] and a variety of vowel contexts. Two of the children used -PO's more often before low than high vowels. We suggest that this vowel-based pattern may result when deaf children learn to lower their larynges in response to visible jaw lowering cues. Another child presented with a pattern of more frequent -Po's before front than back vowels, suggesting that she may have expanded her pharynx anteriorly as she attempted to achieve an anterior tongue placement. Two children also clearly used -Po's more frequently for voiced than voiceless stops, possibly resulting from a tendency to use the degree rather than the timing of vocal fold adduction to distinguish voiceless and voiced phonemes. Two of the children were enrolled in a single-subject multiple baseline study to compare the effectiveness of traditional articulation treatment and visual-feedback treatment. The child who was a far less proficient talker demonstrated rapid and sustained change, whereas the better talker demonstrated minimal change with treatment. This study provides evidence that (a) deaf children use speech production strategies quite unlike those of normally hearing children and (b) deviant speech behaviors of deaf children should be treated before they become part of functional phonological systems. This work highlights the need to consider the unique speech behaviors of deaf children, and their reliance on alternate feedback mechanisms, when developing assessment and treatment procedures.

Although syllabic compression systems are available in many currently marketed hearing aids, the benefit of such systems continues to be debated. The goal of this study was to determine the effect of single-channel amplitude compression on use of speech information were considered, with particular focus on temporal cues. Speech recognition scores were assessed under four conditions, using two types of speech materials. Both temporal and spectral information were provided in the FullSpeech or natural speech stimuli. Unlike previous studies in which use of temporal information may have been confounded by spectral changes, in this study the listener's ability to use temporal information was tested directly using signal-correlated noise (SCN) stimuli, which consisted of a time-varying speech envelope modulating a broad-band noise carrier. Two conditions (FullSpeech and SCN) retained their natural amplitude characteristics. In two corresponding conditions the same stimuli were compressed digitally, using compression parameters appropriate for syllabic compression. This compression reduced the range of time-intensity variations. Recognition scores were obtained from listeners with mild-to-severe sensorineural loss and from a control group of listeners with normal hearing. All stimuli were presented at high levels to reduce potential effects of reduced audibility. Additionally, short-term speech level measurements were compared to individual listener's hearing thresholds to determine the range of speech levels in each frequency region that was audible for each stimulus condition. Results demonstrated no effect of compression on recognition scores for either the FullSpeech or SCN signals for listeners with normal hearing or listeners with hearing loss. This suggests that single-channel syllabic compression processing, of the type used in this study, does not alter the temporal (or spectral) signal sufficiently to cause decreased recognition for VCV syllables when speech audibility is maintained.

The spatiotemporal organization of the mechanically evoked perioral sensorimotor response was sampled from five normal females using a custom-designed linear motor operating under force feedback. Electromyographic activity was sampled from the superior and inferior segments of the orbicularis oris muscle during the production of a visually guided ramp-and-hold lip-rounding task. Brief mechanical inputs of approximately 0.45 N delivered to the left upper lip during the ramp-and-hold task produced a composite myogenic response characterized by phases of excitation and suppression. Modulation of the primary excitatory component (R1) of the mechanically evoked perioral response was found to be highly dependent upon the rate of force recruitment (1 N/s vs. 4 N/s) and the phase of force recruitment (20% vs. 50% vs. 80% of 1 N end-point force). Modulation of later occurring inhibitory (S1) and excitatory (R2) potentials were also found to be dependent upon differences in the rate and phase of force recruitment. The organization of the perioral sensorimotor response is considered in relation to speech motor control and the dynamic organization of neuronal groups subserving perioral sensorimotor activity.

The articulator positions of a subject with a cochlear implant were measured with an electromagnetic midsagittal articulometer (EMMA) system with and without auditory feedback available to the subject via his implant. Acoustic analysis of sibilant productions included specific measures of their spectral properties as well as the F3 formant amplitude. More general postural characteristics of the utterances, such as speech rate and sound level, were measured as well. Because of the mechanical and aerodynamic interdependence of the articulators, the postural variables must be considered before attributing speech improvement to the selective correction of a phonemic target with the use of auditory feedback. The tongue blade position was related to the shape and central tendency of the /integral of/ spectra; however, changes in the spectral contrast between /s/ and /integral of/ were not related to changes in the more general postural variables of rate and sound level. These findings suggest that the cochlear implant is providing this subject with important auditory cues that he can use to monitor his speech and maintain the phonemic contrast between /s/ and /integral of/.

This study reports changes in acoustic, respiratory, laryngeal, and articulatory kinematics of 3 males who stutter, following participation in a version of the Hollins Precision Fluency Shaping Program. Two nonstuttering controls received no treatment. Subjects repeated phrases of the form "He see CVC again" at self-selected slow, normal, and fast speaking rates. For experimental subjects, acoustic duration of the phrases increased significantly in 7 out of 9 comparisons of before- and after-treatment conditions, whereas controls decreased the duration of the phrases in 4 out of 6 comparisons of measurements made over approximately the time interval during which the experimental group received treatment. The experimental group increased inspiratory volume for 7 out of 9 conditions and average expiratory flow significantly for all conditions, whereas the controls decreased both. The experimental group prolonged laryngeal opening in 6 of 7 comparisons, but only 3 of the increases were significant. Lip and jaw movements for consonants were significantly reduced in amplitude for the experimental group for 30 of 36 measures. The direction of change for laryngeal and upper articulator measures was mixed for controls. These results show that behavioral treatment can produce significant changes in the fluent speech of persons who stutter with respect to respiration, laryngeal valving, and articulation. Possible relationships between the observed changes in speech production and the increased fluency of the subjects are discussed.

The purpose of this study was to examine the effects of varying length and linguistic utterance types on temporal acoustic characteristics of the imitative speech of apraxic speakers. Vowel duration and two between-word segment durations were examined during the production of three response types: words, word-strings, and sentences. Three length conditions were studied in words, two length conditions for word-strings, and three length conditions for sentences, yielding eight experimental conditions. Apraxic speakers exhibited significantly longer vowel and between-word segment durations than control speakers in all conditions. Apraxic speakers consistently produced longer vowel and between-word segment durations in sentence contexts than in word contexts. Further, intrasubject and intersubject variability for between-word segment durations were substantially greater for the apraxic speakers in sentences compared to word conditions, whereas control speakers exhibited greater homogeneity in sentence production. The differences in duration and variability in sentence production versus word or word-string production imply different mechanisms for executing motor programs for varying linguistic stimuli.

The Developmental Weighting Shift (DWS) suggests that children adjust the weights they assign to the acoustic parameters of the speech signal as they gain experience with a native language, and that this developmental shift in perceptual weighting strategies is related to another developmental change: increased sensitivity to the phonetic structure of the speech signal. To test these claims, children presumed to differ in the amount of linguistic experience they had received during their preschool years participated in two kinds of tasks: a labeling task designed to estimate differences among groups in the weights assigned to various acoustic parameters, and tasks of phonemic awareness. The experimental groups were children from low-socioeconomic (low-SES) backgrounds, children with histories of chronic otitis media (OM), and children who experienced both conditions. A control group of children who experienced neither of these conditions also participated. The hypotheses were that, because of their diminished linguistic experience, children in the three experimental groups would display both more immature weighting strategies and poorer phonemic awareness than children in the control group, and that developmental advance in perceptual weighting strategies and phonemic awareness would be correlated. Results indicated that children with histories of chronic OM performed more poorly on both kinds of tasks than did children in the control group, and low-SES children performed more poorly still. Children experiencing both low-SES and chronic OM performed no differently than the low-SES children. These results provide support for the claim that the development of mature perceptual weighting strategies for speech and of phonemic awareness are related. Support is also provided for the claim that both depend on receiving sufficient and appropriate experience with a native language during the preschool years.

Following Botulinum Toxin Type A injection, glottal competency of an adductor spasmodic dysphonia patient is thought to vary over a wide range. This study quantifies variability in laryngeal adduction for one such patient over a 10-week period. Analyses of kinematic and aerodynamic measures were used to track the voice weekly. The measures included the electroglottographic waveform width (EGGW50), nondimensional electroglottographic slope quotient (SLQ), glottal flow open quotient (FOQ), dc glottal flow, and nondimensional glottal flow peak quotient (FPQ). The results suggested that change in degree of glottal adduction over time can be observed even when vocal instability is present within each recording session. Perceptual ratings of vocal quality (breathy to pressed) were related to the laryngeal measures. The coefficient of variation for EGGW50 and the percentage of dichrotic phonations reached minima during sessions with predominantly breathy and hypoadducted phonation. The methods used in this study show potential to aid decisions about dose level and sources of perceptual adductor spasmodic dysphonia symptoms for a given patient.