Children with amblyaudia show less flexibility in auditory cortical entrainment to periodic non-speech sounds.

OBJECTIVE: We investigated auditory temporal processing in children with amblyaudia (AMB), a subtype of auditory processing disorder (APD), via cortical neural entrainment. DESIGN AND STUDY SAMPLES: Evoked responses were recorded to click-trains at slow vs. fast (8.5 vs. 14.9/s) rates in n = 14 children with AMB and n = 11 age-matched controls. Source and time-frequency analyses (TFA) decomposed EEGs into oscillations (reflecting neural entrainment) stemming from bilateral auditory cortex. RESULTS: Phase-locking strength in AMB depended critically on the speed of auditory stimuli. In contrast to age-matched peers, AMB responses were largely insensitive to rate manipulations. This rate resistance occurred regardless of the ear of presentation and in both cortical hemispheres. CONCLUSIONS: Children with AMB show less rate-related changes in auditory cortical entrainment. In addition to reduced capacity to integrate information between the ears, we identify more rigid tagging of external auditory stimuli. Our neurophysiological findings may account for domain-general temporal processing deficits commonly observed in AMB and related APDs behaviourally. More broadly, our findings may inform communication strategies and future rehabilitation programmes; increasing the rate of stimuli above a normal (slow) speech rate is likely to make stimulus processing more challenging for individuals with AMB/APD.

Baseline, retest, and post-injury profiles of auditory neural function in collegiate football players.

OBJECTIVES: Recent retrospective studies report differences in auditory neurophysiology between concussed athletes and uninjured controls using the frequency-following response (FFR). Adopting a prospective design in college football players, we compared FFRs before and after a concussion and evaluated test-retest reliability in non-concussed teammates. DESIGN: Testing took place in a locker room. We analysed the FFR to the fundamental frequency (F0) (FFR-F0) of a speech stimulus, previously identified as a potential concussion biomarker. Baseline FFRs were obtained during the football pre-season. In athletes diagnosed with concussions during the season, FFRs were measured days after injury and compared to pre-season baseline. In uninjured controls, comparisons were made between pre- and post-season. STUDY SAMPLE: Participants were Tulane University football athletes (n = 65). RESULTS: In concussed athletes, there was a significant group-level decrease in FFR-F0 from baseline (26% decrease on average). By contrast, the control group's change from baseline was not statistically significant, and comparisons of pre- and post-season had good repeatability (intraclass correlation coefficient = 0.75). CONCLUSIONS: Results converge with previous work to evince suppressed neural function to the FFR-F0 following concussion. This preliminary study paves the way for larger-scale clinical evaluation of the specificity and reliability of the FFR as a concussion diagnostic.HighlightsThis prospective study reveals suppressed neural responses to sound in concussed athletes compared to baseline.Neural responses to sound show good repeatability in uninjured athletes tested in a locker-room setting.Results support the feasibility of recording frequency-following responses in non-laboratory conditions.

Evidence of binaural integration benefits following ARIA training for children and adolescents diagnosed with amblyaudia.

OBJECTIVE: The purpose of this study was to demonstrate the efficacy of Auditory Rehabilitation for Interaural Asymmetry (ARIA) to improve dichotic listening scores in children and adolescents diagnosed with amblyaudia and other binaural integration deficits. DESIGN: The study is a field experiment without randomisation. STUDY: Participants placed into groups based on dichotic listening test scores received four sessions of ARIA training. Baseline scores were compared to performance during the final session of training and to scores obtained 2 or more months after completion of ARIA. SAMPLE: A total of 125 children participated at five different clinical sites. RESULTS: Dichotic listening scores improved across all participants. Post hoc analyses demonstrated highly significant gains in non-dominant ear performance and reductions of interaural asymmetry among participants diagnosed with amblyaudia at both post-ARIA measurements. Participants in other diagnostic groups also showed significant benefits for some post-ARIA measures. CONCLUSIONS: Results demonstrate that ARIA training is an effective method for improving binaural integration skills among children and adolescents identified with dichotic listening weaknesses during assessments for auditory processing disorder (APD), especially for those diagnosed with amblyaudia. Benefits achieved following ARIA training remain stable across several months.

Diagnosis of amblyaudia in children referred for auditory processing assessment.

Children (n = 141) referred to 5 clinical sites for auditory processing disorder assessment were tested with two dichotic listening tests, one with word pairs and the other with pairs of digits, as part of a comprehensive diagnostic battery. Scores from the Randomized Dichotic Digits Test and the Dichotic Words Test were compared to age-appropriate norms and used to place children into one of four diagnostic categories (normal, dichotic dysaudia, amblyaudia, or amblyaudia plus) or to identify them as undiagnosed. Results from the two dichotic tests led to diagnosis of 56% of the children tested, leaving 44% undiagnosed. When results from a third dichotic listening test were used as a tie-breaker among originally undiagnosed children, a total of 79% of the children's scores were placed into diagnostic categories (13% normal, 19% dichotic dysaudia, 35% amblyaudia, 12% amblyaudia plus). Amblyaudia, a binaural integration deficit evident only from dichotic listening test results, was most prevalent (35% + 12% = 47%) in this population of children suspected of auditory processing weaknesses. Since amblyaudia responds to treatment with Auditory Rehabilitation for Interaural Asymmetry (ARIA), clinicians are guided through the protocol for identifying diagnostic categories so that they can make appropriate referrals for rehabilitation.

Behavioral and Cortical Activation Changes in Children Following Auditory Training for Dichotic Deficits.

We report changes following auditory rehabilitation for interaural asymmetry (ARIA) training in behavioral test performance and cortical activation in children identified with dichotic listening deficits. In a one group pretest-posttest design, measures of dichotic listening, speech perception in noise, and frequency pattern identification were assessed before and 3 to 4.5 months after completing an auditory training protocol designed to improve binaural processing of verbal material. Functional MRI scans were also acquired before and after treatment while participants passively listened in silence or to diotic or dichotic digits. Significant improvements occurred after ARIA training for dichotic listening and speech-in-noise tests. Post-ARIA, fMRI activation increased during diotic tasks in anterior cingulate and medial prefrontal regions and during dichotic tasks, decreased in the left precentral gyrus, right-hemisphere pars triangularis, and right dorsolateral and ventral prefrontal cortices, regions known to be engaged in phonologic processing and working memory. The results suggest that children with dichotic deficits may benefit from the ARIA program because of reorganization of cortical capacity required for listening and a reduced need for higher-order, top-down processing skills when listening to dichotic presentations.

Can Videoconferencing Be a Viable Method to Measure Speech Perception?

PURPOSE: Telehealth has proven effective for service delivery to remote and rural locations and was helpful during lockdowns when patients were unable to see clinicians in person. To assure the reliability of clinical services, the aim of the present study was to evaluate a telehealth protocol to measure speech perception skills through virtual meeting applications such as Zoom. METHOD: A total of 20 participants with normal hearing and cognition participated in the study. Participants' speech perception performance was measured in two sessions: one over a Zoom call and one in person in the laboratory. Speech perception was measured using Quick Speech-in-Noise Test, Bamford-Kowal-Bench Speech-in-Noise Test, and Words-in-Noise Test. RESULTS: Statistical analysis revealed no significant differences between speech perception scores obtained over the Zoom and in-person methodologies for any of the tests. Additionally, our study found no significant difference in the scores obtained between wired and wireless headphones during Zoom calls. CONCLUSION: These results suggest that Zoom can be used as a reliable method to measure speech perception in young individuals with normal hearing using these three tests in situations where conventional methods cannot be utilized.

ARIA treatment benefits are related to severity of dichotic listening deficits in children.

PURPOSE: This study investigated the relationship between dichotic listening (DL) benefits from treatment with Auditory Rehabilitation for Interaural Asymmetry (ARIA) and the severity of DL deficits quantified prior to the onset of treatment. We hypothesized that children with more severe DL deficits would demonstrate greater benefits following ARIA. METHOD: A scale that quantifies deficit severity was applied to dichotic listening scores obtained before and after training with ARIA at multiple clinical sites (n = 92). Using multiple regression analyses, we evaluated the predictive effects of deficit severity on DL outcomes. RESULTS: Results demonstrated that deficit severity can predict benefits from ARIA, as measured by improvements in DL scores in both ears. CONCLUSION: ARIA is an adaptive training paradigm for improving binaural integration abilities in children with DL deficits. The results from this study suggest that children with more severe DL deficits achieve greater benefits from ARIA and that a severity scale may provide important clinical information for recommending intervention.

Dichotic listening deficits in children with hearing loss.

PURPOSE: This correlational study compared dichotic listening among children with significant hearing loss to typically developing children and children clinically assessed for auditory processing disorder. METHOD: Recorded versions of two dichotic tests were delivered under earphones or in the sound field for children using amplification. Individual ear scores and interaural asymmetry were compared to normative data. Matched deficit patterns from both tests were identified, ranked for severity of deficit, and compared across groups. Relationships between dichotic scores and factors related to amplification were investigated in the children with hearing loss. RESULTS: Dichotic scores were significantly poorer among children with hearing loss without the large interaural asymmetries seen in children assessed clinically for auditory processing problems. Device type and age of implantation had no effect on scores; non-dominant ear scores on the digits test were significantly correlated to age of device use in the left ear and duration of device use in the right ear. Non-dominant ear scores with digits were also significantly correlated with bilateral word recognition. CONCLUSIONS: Poor dichotic perception in children with significant hearing losses may be related to the use of recorded test materials, immature skills in attention and working memory, or other factors that contribute to development of vocabulary and language. These weaknesses may interfere with successful mainstream educational placement in these children. Assessment of dichotic performance in this population could lead to deficit-specific interventions that may improve outcomes and enhance educational opportunities for children with hearing loss.

Effect of Titrated Exposure to Non-Traumatic Noise on Unvoiced Speech Recognition in Human Listeners with Normal Audiological Profiles.

Non-traumatic noise exposure has been shown in animal models to impact the processing of envelope cues. However, evidence in human studies has been conflicting, possibly because the measures have not been specifically parameterized based on listeners' exposure profiles. The current study examined young dental-school students, whose exposure to high-frequency non-traumatic dental-drill noise during their course of study is systematic and precisely quantifiable. Twenty-five dental students and twenty-seven non-dental participants were recruited. The listeners were asked to recognize unvoiced sentences that were processed to contain only envelope cues useful for recognition and have been filtered to frequency regions inside or outside the dental noise spectrum. The sentences were presented either in quiet or in one of the noise maskers, including a steady-state noise, a 16-Hz or 32-Hz temporally modulated noise, or a spectrally modulated noise. The dental students showed no difference from the control group in demographic information, audiological screening outcomes, extended high-frequency thresholds, or unvoiced speech in quiet, but consistently performed more poorly for unvoiced speech recognition in modulated noise. The group difference in noise depended on the filtering conditions. The dental group's degraded performances were observed in temporally modulated noise for high-pass filtered condition only and in spectrally modulated noise for low-pass filtered condition only. The current findings provide the most direct evidence to date of a link between non-traumatic noise exposure and supra-threshold envelope processing issues in human listeners despite the normal audiological profiles.

Dichotic listening in children: age-related changes in direction and magnitude of ear advantage.

Children between the ages of 5 and 12 years were tested with dichotic listening tests utilizing single syllable words and random presentations of digits. They produced a higher prevalence of left ear dominance than expected, especially among right-handed children when tested with words. Whether more children demonstrate the LEA because of right hemisphere dominance for language or because there is less stability in ear advantage direction at younger ages cannot be fully resolved by this study. When ear advantages were measured by subtracting each child's lower score from the higher score without regard to right or left direction, an age-related trend toward lower measures of ear advantage was evident. This trend was greater for dichotic words than for dichotic digits. Structural factors that may be related to these results and possible influences of attention and verbal workload on the two kinds of dichotic stimuli are discussed.

Defining the Role of Attention in Hierarchical Auditory Processing.

Communication in noise is a complex process requiring efficient neural encoding throughout the entire auditory pathway as well as contributions from higher-order cognitive processes (i.e., attention) to extract speech cues for perception. Thus, identifying effective clinical interventions for individuals with speech-in-noise deficits relies on the disentanglement of bottom-up (sensory) and top-down (cognitive) factors to appropriately determine the area of deficit; yet, how attention may interact with early encoding of sensory inputs remains unclear. For decades, attentional theorists have attempted to address this question with cleverly designed behavioral studies, but the neural processes and interactions underlying attention's role in speech perception remain unresolved. While anatomical and electrophysiological studies have investigated the neurological structures contributing to attentional processes and revealed relevant brain-behavior relationships, recent electrophysiological techniques (i.e., simultaneous recording of brainstem and cortical responses) may provide novel insight regarding the relationship between early sensory processing and top-down attentional influences. In this article, we review relevant theories that guide our present understanding of attentional processes, discuss current electrophysiological evidence of attentional involvement in auditory processing across subcortical and cortical levels, and propose areas for future study that will inform the development of more targeted and effective clinical interventions for individuals with speech-in-noise deficits.

Dichotic listening deficits in amblyaudia are characterized by aberrant neural oscillations in auditory cortex.

OBJECTIVE: Children diagnosed with auditory processing disorder (APD) show deficits in processing complex sounds that are associated with difficulties in higher-order language, learning, cognitive, and communicative functions. Amblyaudia (AMB) is a subcategory of APD characterized by abnormally large ear asymmetries in dichotic listening tasks. METHODS: Here, we examined frequency-specific neural oscillations and functional connectivity via high-density electroencephalography (EEG) in children with and without AMB during passive listening of nonspeech stimuli. RESULTS: Time-frequency maps of these "brain rhythms" revealed stronger phase-locked beta-gamma (~35 Hz) oscillations in AMB participants within bilateral auditory cortex for sounds presented to the right ear, suggesting a hypersynchronization and imbalance of auditory neural activity. Brain-behavior correlations revealed neural asymmetries in cortical responses predicted the larger than normal right-ear advantage seen in participants with AMB. Additionally, we found weaker functional connectivity in the AMB group from right to left auditory cortex, despite their stronger neural responses overall. CONCLUSION: Our results reveal abnormally large auditory sensory encoding and an imbalance in communication between cerebral hemispheres (ipsi- to -contralateral signaling) in AMB. SIGNIFICANCE: These neurophysiological changes might lead to the functionally poorer behavioral capacity to integrate information between the two ears in children with AMB.

A preliminary study on speech recognition in noise training for children with hearing loss.

PURPOSE: The current study is a preliminary study to examine whether children with hearing loss would benefit from a speech recognition in noise training. METHODS: Twenty-five children who wore hearing aids, cochlear implants, or bimodal devices from 4 to 12 years old participated in the study (experimental, n = 16; control, n = 9). The experimental group received a speech-in-noise training that took sixteen 15-min sessions spanning 8 to 12 weeks. The task involves recognizing monosyllabic target words and sentence keywords with various contextual cues in a multi-talker babble. The target stimuli were spoken by two females and fixed at 65 dB SPL throughout the training while the masker varied adaptively. Pre- and post-training tests measured the speech recognition thresholds of monosyllabic words and sentences spoken by two males in the babble noise. The test targets were presented at 55, 65, and 80 dB SPL. RESULTS: The experimental group improved for word and sentence recognition in noise after training (Mean Difference = 2.4-2.5 dB, 2.7-4.2 dB, respectively). Training benefits were observed at trained (65 dB SPL) and untrained levels (55 and 80 dB SPL). The amount of post-training improvement was comparable between children using hearing aids and cochlear implants. CONCLUSIONS: This preliminary study showed that children with hearing loss could benefit from a speech recognition in noise training that may fit into the children's school schedules. Training at a conversational level (65 dB SPL) transfers the benefit to levels 10-15 dB softer or louder. Training with female target talkers transfers the benefit to male target talkers. Overall, speech in noise training brings practical benefits for school-age children with hearing loss.

Auditory processing disorders in incarcerated youth: A call for early detection and treatment.

BACKGROUND: Numerous reports have linked language impairment, academic underachievement, and attention disorder to misbehavior in adolescence. Recent studies have found an association between deficits in hearing and auditory processing and involvement in the juvenile justice system. In fact, the existence of an auditory processing disorder (APD) is a risk factor for adolescent delinquency even in the presence of normal hearing. The nexus between APD, low academic achievement and offending behavior in teens has prompted recommendation for early screening of school children for abnormalities in auditory processing. Using a variety of diagnostic tools, investigators have found an increase in the frequency of APD in cohorts of confined youthful offenders. The present investigation evaluates the prevalence of APD in a group of incarcerated youth residing in a detention center. METHODS: A total of 52 incarcerated adolescents (8 females and 44 males; age range 13-20 (M = 16.0), residing at a juvenile detention center in Pittsburgh, Pennsylvania and determined to have normal auditory acuity were included in the study. All participants were screened for APD using two dichotic listening tests, the Randomized Dichotic Digits Test (RDDT) and the Dichotic Words Test (DWT), evaluative modalities to identify deficits in auditory processing. The prevalence of APD in the study group was compared to previously published normative data for non-offending age-matched youth. RESULTS: On the RDDT, 23.1% of participants demonstrated normal auditory processing, while 77% had abnormal test results. On the DWT, 75% of subjects exhibited normal auditory processing, while the scores were abnormal for 24.9%. When the results of the RDDT and the DWT were combined to establish a pattern for the purpose of interpreting a deficit, 21.1% of the participants produced results that were within normal limits, while 17.3% qualified for a diagnosis of APD, with abnormal results on both tests. Previous studies have estimated the prevalence of auditory processing disorder in the general adolescent population as being between 2% and 7%. CONCLUSIONS: This study found a higher prevalence of auditory processing disorder in a cohort of incarcerated youth compared with age-matched controls. Diagnostic screening protocols that identify at-risk children have been developed, as have effective therapies to improve auditory processing function. Teachers, pediatricians and psychologists should consider APD in children and adolescents with behaviors that may increase their risk for juvenile justice involvement. Studies on optimal timing and strategies for assessing and treating APD in children and adolescents are needed, including youth caught up in the juvenile justice system.

Recognition of randomly presented one-, two-, and three-pair dichotic digits by children and young adults.

PURPOSE: To establish normative data for children and to characterize developmental differences in performance with the free recall version of the Randomized Dichotic Digits Test. RESEARCH DESIGN: Group comparison of behavioral data derived from administration of the Randomized Dichotic Digits Test. STUDY SAMPLE: Children from 10 to 18 years of age (167) and young adults from 19 to 28 years of age (50). RESULTS: Performance improved with age across all types of digit pairs, especially in the left ear, leading to smaller interaural asymmetries among older participants. A left-ear advantage was produced by 39 subjects (18%), only two of whom were left-handed. Normative data are reported for right and left ear scores and for interaural asymmetry (percent correct difference between the two ears) under one-, two-, and three-pair conditions of the test and for interaural asymmetry across the entire test. A unilateral deficit was identified in children (15.5%) and young adults (12%) for the left ear and in children (11.3%) and young adults (6%) for the right ear. A bilateral deficit was also identified in children (6.5%) and young adults (6%). CONCLUSIONS: This test may be useful as part of the clinical battery for identifying binaural integration weaknesses and referring individuals for auditory rehabilitation for interaural asymmetry (ARIA).

Auditory rehabilitation for interaural asymmetry: preliminary evidence of improved dichotic listening performance following intensive training.

Children with dichotic left ear deficits received intensive training in phase I and phase II clinical trials designed to establish the efficacy of directly training dichotic listening. Dichotic verbal material was presented in the sound field with intensity adjusted separately for each speaker. Output from the right-sided speaker was initially 20-30 db HL lower than for the left-sided speaker, resulting in excellent performance in the left ear. Intensities were adaptively adjusted throughout training in 1, 2, and 5-dB steps in order to keep performance high across dichotic tasks. In both phase I (n=8) and phase II (n=13) trials, children demonstrated significant gains in dichotic left ear performance after training. In phase II, children also demonstrated significant gains in right ear performance. Overall results from the two trials support the feasibility of this training approach for improving a larger than normal interaural asymmetry on dichotic listening tasks. Significant improvements in language comprehension and word recognition in phase II suggest that this type of training may also facilitate language skills in some children.

Hemodynamic differences in children with dichotic listening deficits: preliminary results from an fMRI study during a cued listening task.

Functional magnetic resonance images were acquired while children with and without dyslexia identified incongruous words embedded within fairy tale segments in a quasidichotic listening task. All children produced greater activation in the left hemisphere than in the right hemisphere during the binaural separation listening task. Children with dyslexia, who had a higher incidence of a dichotic left ear deficit from prescanning behavioral tests, produced fewer hits and more misses than control children while monitoring their left ears in the scanner. Control children produced stronger left hemispheric activation for ipsilateral left ear input than right hemispheric activation for ipsilateral right ear input, but ipsilateral activation patterns in children with dyslexia were symmetrical. Children with dyslexia who monitored their right ears first produced the lowest left hemispheric activation overall, suggesting that priming of the right ear may have inhibited the ability of children with a left ear deficit to adequately identify target words presented toward their left ears while in the scanner.

Auditory processing disorders: an update for speech-language pathologists.

PURPOSE: Unanswered questions regarding the nature of auditory processing disorders (APDs), how best to identify at-risk students, how best to diagnose and differentiate APDs from other disorders, and concerns about the lack of valid treatments have resulted in ongoing confusion and skepticism about the diagnostic validity of this label. This poses challenges for speech-language pathologists (SLPs) who are working with school-age children and whose scope of practice includes APD screening and intervention. The purpose of this article is to address some of the questions commonly asked by SLPs regarding APDs in school-age children. This article is also intended to serve as a resource for SLPs to be used in deciding what role they will or will not play with respect to APDs in school-age children. METHOD: The methodology used in this article included a computerized database review of the latest published information on APD, with an emphasis on the work of established researchers and expert panels, including articles from the American Speech-Language-Hearing Association and the American Academy of Audiology. CONCLUSIONS: The article concludes with the authors' recommendations for continued research and their views on the appropriate role of the SLP in performing careful screening, making referrals, and supporting intervention.

A Nonsense Consonant-Vowel-Consonant Word Test to Assess Auditory Processing.

BACKGROUND: Dichotic listening (DL), or how the two ears work together as a team, is often used in the assessment of auditory processing disorders in both children and adults. Currently, the battery of dichotic tests includes stimuli containing words, digits, and nonsense consonant-vowel syllables. Single-syllable nonsense words are of particular use in assessing processing abilities because they can evaluate auditory processing without a listener's dependence on linguistic knowledge. Therefore, nonsense words may assess auditory processes independently of previous vocabulary knowledge. PURPOSE: This study is designed to assess the clinical applicability and face validity of a nonsense word DL test in a young adult population. RESEARCH DESIGN: This study included an experimental design to investigate the performance of young adult listeners on a Dichotic Nonsense Word (DNW) test spoken by a male and female speaker. The results were compared with one study that investigated young adult listener's performance on dichotic tests of English words. STUDY SAMPLE: A total of 100 young adult participants were recruited from the School of Health and Rehabilitation Sciences at the University of Pittsburgh to participate in the study. The participants ranged in age from 20 to 30, with an average age of 23, and all participants had normal hearing. DATA COLLECTION AND ANALYSIS: DL performance was measured in all participants using the Dichotic Words Test (DWT) and the newly developed DNW test. Kolmogorov-Smirnoff tests of normality were used to assess distribution of right- and left-ear scores. Criterion cutoff scores were determined for the percent correct scores in the nondominant ear and dominant ear and for ear advantage. RESULTS: Scores were significantly different between the two tests in the right ear, Z = -8.258, p < 0.001, and in the left ear, Z = -8.471, p < 0.001. Scores within each test were higher for the right ear than for the left ear, and scores for both ears were significantly lower on the DNW test than for the DWT. Ear advantage scores from the DNW test were significantly larger than those obtained from the DWT. The low and high 95% criterion cutoff ranges for the DNW test were considerably wider than the 95% criterion cutoff ranges for the DWT. CONCLUSIONS: Results indicate that the new DNW test may be a useful clinical tool within a test battery for evaluating auditory processing skills independent of vocabulary knowledge.