Evaluation of central auditory processing in children with developmental dyslexia.

Auditory processing is the analysis of sounds' attributions such as localization, lateralization, temporality, frequency, loudness, phase, auditory memory and auditory attention through primer and secondar central auditory paths. This study aims to show that music contributes on auditory processing by applying central auditory tests on two groups who are musicians and nonmusicians. The participants in this study are aged between 20 and 40. The mean age of the musician participants is 24.40±3.811, when the mean age of non-musician participants is 26.07±4.525. Each group has 30 participants. All participants got examined for otorhinolaryngology and they were tested for pure tone audiometry and immitansmetric measurement. For musician participants, this study included people who have professional music career for at least 5 years and for non-musician participants, it has been included those who are capable of normal hearing. All participants tested for Frequency Patterns Test (FPT), Duration Patterns Test (DPT), Random Gap Detection Test (RGDT) and Staggered Spondaic Word Test (SSWT). The results of the FPT, DPT, RGDT and SSWT tests applied to musician and non-musician participants indicate that there is a statistical significance on auditory processing between these two groups (p<0.05). It is founded that there is a considerable difference as a result of statistical significance between the tests from right to left and from left to right (p<0.05). In addition, it is founded that musician participants have much more comprehension ability in the tests from left to right than the tests from right to lefts. This study indicates that people who are interested in music professionally have developed auditory processing skills and senses than people who does not show any professional interest in music.

Voice Quality and Auditory Processing in Subjects with and Without Musical Experience

Modulation of auditory temporal processing, speech in noise perception, auditory-verbal memory, and reading efficiency by anodal tDCS in children with dyslexia

Purpose: to assess whether there is a relationship between temporal auditory processing skills and altered distinctive features in cases of phonological disorder. Methods: 18 children aged between 6 and 8 years, diagnosed with phonological disorders participated in the research. All children underwent speech-language screening, phonological assessment and the assessment of temporal processing skills through the GIN - Gap in Noise Test, TPF - Frequency Pattern Test and TPD - Duration Pattern Test. The numbers of altered phonemes and distinctive features and the level at which they were in the Implicational Model of Features Complexity were compared with those of the GIN, TPF and TPD tests. The significance level adopted for all statistical tests was 5% (p&lt;0.05). Results: in no comparison and correlation was there statistical significance, but the subjects evaluated showed low performance in temporal auditory processing tasks, according to normative testing standards. Conclusion: in the general analysis, there was no relationship between temporal auditory skills and distinctive traits in the population assessed, even though they had difficulties in temporal auditory processing tasks.

The Staggered Spondaic Word (SSW) Test was developed as a means to assess central auditory function. In the present study, the SSW Test was administered to a group of normal-hearing young adults (N = 86) with nor history of centra auditory problems in an attempt to evaluate previous normative data and the types of errors made by this group. Mean number of errors for corrected (C-SSW) scores were consistent with the "normal" category established by Katz. Response bias (ear effects, order effects, and reversals) was not prevalent in this population. Although two subjects obtained a significant number of reversals, it seemed that changes in listening strategy rather than auditory dysfunction was accountable for this finding.

central auditory processing and exposure to metallic mercury. to evaluate the performance on tests of central auditory processing in adolescents exposed to metallic mercury. participants were 52 adolescents, of both genders, who presented hearing thresholds within normal limits. The study group (SG) was composed by 21 adolescents who worked on the burning of gold-mercury amalgams, on the re-burning of gold in stores that sell this metal or who lived next to gold mines or gold shops. The control group (CG) was composed by 31 adolescents who had no history of exposure to mercury. Investigation procedures included the application of a clinical, occupational and mercury exposure history questionnaire, basic audiometric assessment as well as central auditory processing tests. Statistical significant differences in the auditory processing tests of non-verbal sound sequence memory test (p = 0,001), frequency pattern test (p = 0,000), duration pattern test (p = 0,000) and SSW test in Portuguese (p = 0,006) were observed between SG and CG. adolescents exposed to metallic mercury presented a lower performance on most of the auditory processing tests when compared to those who had no history of exposure to mercury. The main deficit found in the study was related to difficulty in distinguishing successive brief sounds.

Deficits in identification and discrimination of sounds with short inter-stimulus intervals or short formant transitions in children with specific language impairment (SLI) have been taken to reflect an underlying temporal auditory processing deficit. Using the sustained frequency following response (FFR) and the onset auditory brainstem responses (ABR) we evaluated if children with SLI show abnormalities at the brainstem level consistent with a temporal processing deficit. To this end, the neural encoding of tonal sweeps, as reflected in the FFR, for different rates of frequency change, and the effects of reducing inter-stimulus interval on the ABR components were evaluated in 10 4-11-year-old SLI children and their age-matched controls. Results for the SLI group showed degraded FFR phase-locked neural activity that failed to faithfully track the frequency change presented in the tonal sweeps, particularly at the faster sweep rates. SLI children also showed longer latencies for waves III and V of the ABR and a greater prolongation of wave III at high stimulus rates (>30/sec), suggesting greater susceptibility to neural adaptation. These results taken together appear to suggest a disruption in the temporal pattern of phase-locked neural activity necessary to encode rapid frequency change and an increased susceptibility to desynchronizing factors related to faster rates of stimulus presentation in children with SLI.

Background/Aims: Specific language impairment (SLI) is believed to be associated with nonverbal auditory (NVA) deficits. It remains unclear, however, whether children with SLI show deficits in auditory time processing, time processing in general, frequency discrimination (FD), or NVA processing in general. Patients and Methods: Twenty-seven children (aged 8–11) with SLI and 27 control children (CG), matched for age and gender, were retrospectively compared with regard to their performance on five NVA skills in terms of just noticeable differences (JND) and time order judgments (TOJ). JND was used for FD, intensity discrimination, and gap detection, while TOJ was used for FD and clicks. Results: Children with SLI performed significantly worse than the CG only on the FD tasks (JND and TOJ). The other nonverbal tasks showed no significant intergroup differences. Additionally, moderate associations were found between the FD tasks and phonological skills, as well as between FD tasks and language scores. Conclusion: Children with SLI appear to have restricted FD skills compared to controls, but there was no evidence for a common NVA deficit or reduced temporal auditory abilities.

Introduction Stuttering is a human communication disorder characterized by involuntary interruptions to speech flow. Electrophysiological tests and behavioral evaluations allow the neuroaudiological processes involved in stuttering to be investigated. Objective To investigate group differences in the central auditory system using long-latency auditory evoked potentials, cognitive potentials, and behavioral assessments in children who stutter and compare them with fluent children. Methods We assessed 18 children with stuttering and compared them with a control group of 18 children without speech or language impairment. All children were evaluated with pure tone and speech audiometry, acoustic immittance measures, brainstem auditory evoked potentials, long latency auditory evoked potentials, cognitive potentials, and behavioral tests of auditory processing - Random Gap Detection Test (RGDT), Dichotic Digit Test (DDT); Duration Pattern Test (DPT); Pediatric Speech Intelligibility (PSI); and Masking Level Difference (MLD). The Scale of Auditory Behaviors (SAB) questionnaire was also applied. Results Children who stuttered had longer latencies of the P2 and P3 waves compared with the fluent group. There was no difference in P2 amplitudes, but there was a smaller P3 amplitude in children who stuttered, and they also showed significant alterations in the DDT and DPT. Furthermore, an association was found between increased P2 and P3 latency and SAB scores. Conclusion The present study indicates that children who stutter tend to have decreased auditory ability in terms of central auditory processing, and this shows up psychophysically and on the SAB questionnaire.

To verify if there is an association between temporal auditory tests and phonological awareness in individuals with reading and writing disorders. Sixteen children were subjects of this study, aged between 7 and 12 years old, who had reading and writing disorders confirmed after specific assessment. All participants underwent phonological awareness assessment using CONFIAS test. In order to assess the auditory temporal processing, duration and frequency pattern tests were used. The descriptive analysis indicated low performance in syllabic and phonemic activities of phonological awareness as well as in temporal auditory tests. Fisher's test indicated association between disorders in auditory temporal processing and phonological awareness (p>0.001). It suggests that disorders in temporal processing contribute to low performance in phonological awareness tasks. There was association between performance in temporal auditory tests and in the phonological awareness. Data found provide reflections about including temporal auditory assessment among procedures used in the analysis of individuals with reading and writing disorders.

Preschool impairments in auditory processing and speech perception uniquely predict future reading problems

IntroductionTraumatic brain injury can impair the central auditory pathways and auditory cortex. Hence, individuals who suffered a traumatic brain injury may be at risk of central auditory processing disorders, which can be identified with behavioral tests that assess central auditory function. ObjectiveTo characterize and compare the performance of children and adolescents with and without a history of traumatic brain injury in behavioral tests that assess central auditory processing. MethodThe sample comprised 8- to 18-year-old individuals of both sexes who suffered moderate or severe closed traumatic brain injury 3 to 24 months before their participation in the study and whose hearing thresholds were normal. These individuals were matched for sex and age with other subjects without a history of traumatic brain injury and submitted to behavioral assessment of the central auditory processing with special tests to assess hearing skills (namely, auditory closure, figure-ground, and temporal processing), selected according to their chronological age and response-ability. ResultsThe study group performed statistically worse than the comparison group in auditory closure, figure-ground in verbal dichotic listening, and temporal ordering. The central auditory processing tests with abnormal results in the comparison group were different from those in the study group. ConclusionCentral auditory processing disorders were identified in all subjects of the study group, especially involving auditory closure and temporal processing skills, in comparison with subjects without a history of traumatic brain injury.

The effect of lead on the avian auditory brainstem

Studies of basic (nonspeech) auditory processing in adults thought to have developmental dyslexia have yielded a variety of data. Yet there has been little consensus regarding the explanatory value of auditory processing in accounting for reading difficulties. Recently, however, a number of studies of basic auditory processing in children with developmental dyslexia have suggested that a reduced ability to discriminate the rate of change in amplitude envelope onsets (rise time) may be linked to phonological processing difficulties and thereby to reading difficulties. Here, we select a range of different rise-time tasks used with children, and give them to adults with developmental dyslexia, along with 2 other auditory tasks (intensity discrimination and temporal order judgment). Deficits in both rise-time perception and temporal order judgment were found to predict literacy attainment in adults with developmental dyslexia, but the data were suggestive of different causal pathways.

People suffering from age-related hearing loss typically present with deficits in temporal processing tasks. Temporal processing deficits have also been shown in single-unit studies at the level of the auditory brainstem, midbrain, and cortex of aged animals. In this study, we explored whether temporal coding is already affected at the level of the input to the central auditory system. Single-unit auditory nerve fiber recordings were obtained from 41 Mongolian gerbils of either sex, divided between young, middle-aged, and old gerbils. Temporal coding quality was evaluated as vector strength in response to tones at best frequency, and by constructing shuffled and cross-stimulus autocorrelograms, and reverse correlations, from responses to 1 s noise bursts at 10-30 dB sensation level (dB above threshold). At comparable sensation levels, all measures showed that temporal coding was not altered in auditory nerve fibers of aging gerbils. Furthermore, both temporal fine structure and envelope coding remained unaffected. However, spontaneous rates were decreased in aging gerbils. Importantly, despite elevated pure tone thresholds, the frequency tuning of auditory nerve fibers was not affected. These results suggest that age-related temporal coding deficits arise more centrally, possibly due to a loss of auditory nerve fibers (or their peripheral synapses) but not due to qualitative changes in the responses of remaining auditory nerve fibers. The reduced spontaneous rate and elevated thresholds, but normal frequency tuning, of aged auditory nerve fibers can be explained by the well known reduction of endocochlear potential due to strial dysfunction in aged gerbils.SIGNIFICANCE STATEMENT As our society ages, age-related hearing deficits become ever more prevalent. Apart from decreased hearing sensitivity, elderly people often suffer from a reduced ability to communicate in daily settings, which is thought to be caused by known age-related deficits in auditory temporal processing. The current study demonstrated, using several different stimuli and analysis techniques, that these putative temporal processing deficits are not apparent in responses of single-unit auditory nerve fibers of quiet-aged gerbils. This suggests that age-related temporal processing deficits may develop more central to the auditory nerve, possibly due to a reduced population of active auditory nerve fibers, which will be of importance for the development of treatments for age-related hearing disorders.