Monthly Archives: April 2011
Multiple Auditory Steady State Response Thresholds to Bone Conduction Stimuli in Adults With Normal and Elevated Thresholds
Conclusions: The threshold difference scores and correlations in individuals with SNHL are similar to those in normal listeners with simulated SNHL. These difference scores are also similar to those shown by previous studies for the AC-ASSR in individuals with SNHL, at least for 1000 to 4000 Hz. The BC-ASSR provides a reasonably good estimate of BC behavioral threshold in adults, especially between 1000 and 4000 Hz. Further research is required in infants with hearing loss.
from Ear and Hearing
Predicting the Intelligibility of Vocoded Speech
Conclusions: The present study demonstrated that some of the speech intelligibility indices that have been found previously to correlate highly with wideband speech can also be used to predict the intelligibility of vocoded speech. Both the coherence-based and STI-based measures have been found to be good measures for modeling the intelligibility of vocoded speech. The highest correlation (r = 0.96) was obtained with a derived coherence measure that placed more emphasis on information contained in vowel/consonant spectral transitions and less emphasis on information contained in steady sonorant segments. High (100 Hz) modulation rates were found to be necessary in the implementation of the STI-based measures for better modeling of the intelligibility of vocoded speech. We believe that the difference in modulation rates needed for modeling the intelligibility of wideband versus vocoded speech can be attributed to the increased importance of higher modulation rates in situations where the amount of spectral information available to the listeners is limited (eight channels in our study). Unlike the traditional STI method that has been found to perform poorly in terms of predicting the intelligibility of processed speech wherein nonlinear operations are involved, the STI-based measure used in the present study has been found to perform quite well. In summary, the present study took the first step in modeling the intelligibility of vocoded speech. Access to such intelligibility measures is of high significance as they can be used to guide the development of new speech coding algorithms for cochlear implants.
from Ear and Hearing
The Efficiency of the Single- Versus Multiple-Stimulus Auditory Steady State Responses in Infants
Conclusions: The amplitude reductions seen in the multiple-stimulus conditions in infants, not seen in adults, could be related to maturational differences in the ear canal, middle ear, cochlea, and/or brain stem. Because greater interactions occur in the DM-stimulus condition compared with the monotic multiple-stimulus condition and baseline single-stimulus condition, brain stem origins of these interactions are likely. Study B revealed statistically nonsignificant differences between threshold for 500 Hz when presented in the single- and DM-stimulus conditions. In summary, as with adults, multiple-stimulus presentation in infants is more efficient than single AM tones, at least for 60 dB SPL stimuli.
from Ear and Hearing
Weighting Function-Based Mapping of Descriptors to Frequency-Gain Curves in Listeners With Hearing Loss
Conclusions: The current approach for descriptor-to-FGC mapping is a quick, reliable method for determining individualized changes to the FGC. Given the range of individual differences in the specifics of the descriptor-to-FGC mappings observed, this approach could be useful in a clinical setting to easily quantify these acoustic parameters. Implementation of such procedures could lead to more personalized fine-tuning of amplification devices.
from Ear and Hearing
Systematic review and meta-analyses of RCTs examining tinnitus management
Conclusions:
The efficacy of most interventions for tinnitus benefit remains to be demonstrated conclusively. In particular, high-level assessment of the benefit derived from those interventions most commonly used in practice, namely hearing aids, maskers, and TRT, needs to be performed.
from The Laryngoscope
Building Oral Reading Fluency With Peer Coaching
Fluent oral reading is an essential literacy skill, and data suggest that it is a consistent and persistent problem for many elementary school children. Peer-mediated instruction in which students work together to support each other is an evidence-based practice for improving performance in a variety of academic areas. In this study, we investigated the effectiveness of a peer-mediated fluency-building intervention for struggling readers in second grade. The intervention was provided to small groups of students referred to as difficult-to-remediate, treatment resisters, nonresponders, or lower responders in similar research. Oral reading fluency performance for students who received supplemental intervention (n = 17) was statistically significantly better than that for their peers who received only typical classroom instruction (n = 17). The effects of enhanced fluency instruction were evident across multiple benchmarks, and significant relationships were evident between oral reading fluency and comprehension. The authors discuss the findings in the context of similar peer-mediated interventions and the emerging development of targeted interventions to support response-to-intervention practices.
Children With Autism Spectrum Disorder and Literacy Instruction: An Exploratory Study of Elementary Inclusive Settings
Little is known about how children with autism spectrum disorder (ASD) experience reading instruction in the context of a natural learning environment. This qualitative study centered on three students with ASD who received reading instruction primarily in the general education classroom setting. Observation, interview, and archival data were collected and analyzed to learn how students with ASD engaged in reading instruction and responded to teacher strategies employed to facilitate learning. Findings describe the strengths shown and challenges experienced by children with ASD during literacy instruction. Limited exposure to systematic comprehension instruction hindered the literacy acquisition of learners ASD. Implications for general and special educators are described.
Normative Data for Rey’s Auditory Verbal Learning Test in Individuals with Schizophrenia
Deficits in episodic memory, related to medial temporal lobe dysfunction, are a core component of schizophrenia. Rey’s Auditory Verbal Learning Test (RAVLT) is one of the most widely used neuropsychological memory tasks in clinical practice but normative data are limited. Over the last 15 years, the RAVLT has been used to assess verbal episodic memory performance as part of the Western Australian Family Study of Schizophrenia (WAFSS). This study aims to provide RAVLT norms, derived from the WAFSS, for individuals meeting DSM-IV and ICD-10 diagnostic criteria for schizophrenia or schizophrenia-spectrum disorder, for use in clinical settings. Performance on three immediate and one delayed recall trials, and additional measures of encoding and forgetting, is presented for 492 patients and 260 healthy community controls. Results indicated that age and sex (both groups) and IQ (schizophrenia group only) significantly influenced performance. Norms are presented, as means and standard deviations, stratified accordingly. Additional between-groups analysis clearly shows a significant memory deficit in schizophrenia even when patients are matched on IQ, age, and sex with healthy controls.
Psychometric Data for the Revised Token Test in Normally Developing Mexican Children Ages 4–12 Years
Language comprehension is vital to social and educational development but few pediatric tests are available for its assessment. To approach this problem, two versions of the Token Test (TT), “TT short form” (DeRenzi & Faglioni, 1978) and “Revised Token Test” (RTT), were first compared. Using a sample of 88 normally developing Spanish-speaking children, the tests were compared on their: (a) established psychometric development and (b) internal consistency. The RTT was judged to be superior and was selected for additional experimentation. The RTT was compared with a developmental measure of lexical knowledge on a cross-sectional sample of 250 4–12-year-old normally developing Spanish-speaking children. A significant positive and high correlation supports its concurrent validity. Significant differences across the age groups, along with a principal component analysis that yielded a three-factor structure, support its construct validity. Preliminary normative data across the nine age groups are provided.
The Influence of Inattention and Rapid Automatized Naming on Reading Performance
The current study examined the relation between attention, rapid automatized naming (RAN), and reading fluency among typically developing children. A total of 104 third- and fourth-grade children (8–11 years of age) completed RAN measures consisting of four stimuli (letter, digit, color, and object) and an oral reading fluency measure from the Gray Oral Reading Test-Fourth Edition. Correlational and hierarchical regression analyses revealed that all four RAN stimuli, particularly letter RAN, were significant predictors of reading fluency. Additionally, parent and teacher ratings of inattention from the Swanson, Nolan and Pelham-Version Four rating scale predicted RAN after controlling for gender, working memory, and estimated IQ. Further analyses indicated that RAN performance mediated the relation between inattention and reading fluency. Results support the need to consider attentional variables when assessing reading performance, even among typically developing children.
Infant ability to tell voices apart rests on language experience
A visual fixation study tested whether 7-month-olds can discriminate between different talkers. The infants were first habituated to talkers producing sentences in either a familiar or unfamiliar language, then heard test sentences from previously unheard speakers, either in the language used for habituation, or in another language. When the language at test mismatched that in habituation, infants always noticed the change. When language remained constant and only talker altered, however, infants detected the change only if the language was the native tongue. Adult listeners with a different native tongue from the infants did not reproduce the discriminability patterns shown by the infants, and infants detected neither voice nor language changes in reversed speech; both these results argue against explanation of the native-language voice discrimination in terms of acoustic properties of the stimuli. The ability to identify talkers is, like many other perceptual abilities, strongly influenced by early life experience.
Adaptation to steady-state electrical stimulation of the vestibular system in humans.
Efforts are being made toward the development of a vestibular implant. If such a device is to mimic the physiology of the vestibular system, it must first be capable of restoring a baseline or “rest” activity in the vestibular pathways and then modulating it according to the direction and velocity of head movements. The aim of this study was to assess whether a human subject could adapt to continuous electrical stimulation of the vestibular system, and whether it was possible to elicit artificial smooth oscillatory eye movements via modulation of the stimulation.One bilaterally deaf patient with bilateral vestibular loss received a custom-modified Med-E1 cochlear implant in which one electrode was implanted in the vicinity of the left posterior ampullary nerve. This electrode was activated with biphasic pulse trains of 400-micros phase duration delivered at a repetition rate of 200 pulses per second. The resulting eye movements were recorded with 2-dimensional binocular video-oculography.Successive “on-off” cycles of continuous electrical stimulation resulted in a progressively shorter duration of the nystagmic response. Once the adapted state was reached upon constant stimulation, amplitude or frequency modulations of electrical stimulation produced smooth oscillatory conjugated eye movements.Although this is a case study of one patient, the results suggest that humans can adapt to electrical stimulation of the vestibular system without too much discomfort. Once the subject is in the adapted state, the electrical stimulation can be modulated to artificially elicit smooth eye movements. Therefore, the major prerequisites for the feasibility of a vestibular implant for human use are fulfilled.
Objective methods of sample selection in acoustic analysis of voice.
In acoustic voice analysis, the fact that reproducible methods of sample selection have not been defined impedes research study generalizability and clinical assessment of treatment efficacy. Because perturbation results differ along a single signal, this study sought to establish objective methods of sample selection by use of a moving window to determine the most stable regions of phonation.Voice signals obtained from 21 patients affected by laryngeal conditions associated with Parkinson’s disease were analyzed to study jitter, shimmer, signal-to-noise ratio, and correlation dimension parameters when various sample selection procedures were used. Objectively selected voice samples were chosen based upon 5%, 10%, and 20% variance from a signal’s minimum perturbation value. The stability of these samples, defined by the standard deviations of the acoustic measurements, was compared to the stability of unselected samples and subjectively selected samples.A significant decrease in standard deviation values of acoustic parameters was found in comparing the objectively selected samples (particularly those selected with 5% and 10% variance) to the subjectively selected and unselected samples.These results suggest that the development of an objective sample selection method may have significant effects on the stability and reliability of acoustic voice measurements.
Phenotypes of two Dutch DFNA3 families with mutations in GJB2.
We describe the phenotype of 2 Dutch DFNA3 families with mutations in the GJB2 gene.Two patients from family 1 and one isolated patient from family 2 were studied. The audiometric examination consisted of pure tone and speech audiometry. Two patients underwent vestibular testing and high-resolution computed tomographic scanning of the temporal bone. Mutation analysis of GJB2 and GJB6 was performed.All 3 patients had severe to profound sensorineural hearing impairment. Cochlear implantation was performed in 2 patients, and their phoneme recognition scores were good. Mutation analyses revealed a p.Arg184Gln mutation in GJB2 in family 1 and a p.Arg75Trp mutation in GJB2 in family 2. No mutations in GJB6 were identified. Vestibular function tests and computed tomographic scans yielded normal findings in the examined subjects.Severe to profound sensorineural hearing impairment was found in these DFNA3 patients, and was well rehabilitated with cochlear implantation. A thorough genotype-phenotype correlation is difficult because of the small number of affected patients and the limited clinical data of these patients. More clinical data on DFNA3 families need to be published in order to create a reliable and precise phenotype characterization.
A Figure of Merit for Vocal Attack Time Measurement
Conclusions
A companion metric, Pearson’s r, can be readily obtained to assess the quality of VAT measurement. Decisions to retain or disregard VAT measures may therefore be made on the basis of measurement quality rather than on the basis of group statistics.
from the Journal of Voice
