A phase 2a study investigating the effects of ritlecitinib on brainstem auditory evoked potentials and intraepidermal nerve fiber histology in adults with alopecia areata.

Reversible axonal swelling and brainstem auditory evoked potential (BAEP) changes were observed in standard chronic (9-month) toxicology studies in dogs treated with ritlecitinib, an oral Janus kinase 3/tyrosine kinase expressed in hepatocellular carcinoma family kinase inhibitor, at exposures higher than the approved 50-mg human dose. To evaluate the clinical relevance of the dog toxicity finding, this phase 2a, double-blind study assessed BAEP changes and intraepidermal nerve fiber (IENF) histology in adults with alopecia areata treated with ritlecitinib. Patients were randomized to receive oral ritlecitinib 50 mg once daily (QD) with a 4-week loading dose of 200 mg QD or placebo for 9 months (placebo-controlled phase); they then entered the active-therapy extension and received ritlecitinib 50 mg QD (with a 4-week loading dose of 200 mg in patients switching from placebo). Among the 71 patients, no notable mean differences in change from baseline (CFB) in Waves I-V interwave latency (primary outcome) or Wave V amplitude on BAEP at a stimulus intensity of 80 dB nHL were observed in the ritlecitinib or placebo group at Month 9, with no notable differences in interwave latency or Wave V amplitude between groups. The CFB in mean or median IENF density and in percentage of IENFs with axonal swellings was minimal and similar between groups at Month 9. Ritlecitinib treatment was also not associated with an imbalanced incidence of neurological and audiological adverse events. These results provide evidence that the BAEP and axonal swelling finding in dogs are not clinically relevant in humans.

Diffusion-Weighted Magnetic Resonance Imaging (dMRI) and Cochlear Implant Outcomes in Axonal Auditory Neuropathy: A Case Report.

BACKGROUND: Progressive auditory dysfunction is common in patients with generalized neurodegenerative conditions, but clinicians currently lack the diagnostic tools to determine the location/degree of the pathology and, hence, to provide appropriate intervention. In this study, we present the white-matter microstructure measurements derived from a novel diffusion-weighted magnetic resonance imaging (dMRI) technique in a patient with axonal auditory neuropathy and consider the findings in relation to the auditory intervention outcomes. METHODS: We tracked the hearing changes in an adolescent with Riboflavin Transporter Deficiency (Type 2), evaluating the sound detection/discrimination, auditory evoked potentials, and both structural- and diffusion-weighted MRI findings over a 3-year period. In addition, we explored the effect of bilateral cochlear implantation in this individual. RESULTS: Between the ages of 15 years and 18 years, the patient showed a complete loss of functional hearing ability. The auditory brainstem response testing indicated an auditory neuropathy with evidence of normal cochlear function but disrupted auditory neural activity. While three structural MRI assessments across this period showed a clinically normal cochleovestibular anatomy, the dMRI evaluation revealed a significant loss of fiber density consistent with axonopathy. The subsequent cochlear implant function was affected with the high levels of current required to elicit auditory sensations and concomitant vestibular and facial nerve stimulation issues. CONCLUSIONS: The case study demonstrates the ability of dMRI technologies to identify the subtle white-matter microstructure changes in the auditory pathway, which may disrupt the neural function in patients with auditory axonopathy.

Evaluating benefits of remote microphone technology for adults with hearing loss using behavioural and predictive metrics.

OBJECTIVE: To investigate the benefit of remote-microphone (RM) systems for adults with sensory hearing loss. DESIGN: Speech recognition in quiet and in background noise was assessed. Participants with hearing loss underwent testing in two device conditions: hearing aids (HAs) alone and HAs with a RM. Normal hearing participants completed testing in the unaided condition. Predictive speech intelligibility modelling using the Hearing-Aid Speech Perception Index (HASPI) was also performed on recordings of HA processed test material. STUDY SAMPLE: Twenty adults with sensory hearing loss and 10 adults with normal hearing participated. RESULTS: Speech recognition for participants with hearing loss improved significantly when using the RM compared to HAs alone fit to Phonak's proprietary prescription. Largest benefits were observed in the most challenging conditions. At the lowest signal-to-noise ratio, participants with hearing loss using a RM outperformed normal hearing listeners. Predicted intelligibility scores produced by HASPI were strongly correlated to behavioural results. CONCLUSIONS: Adults using HAs who have significant difficulties understanding speech in noise will experience considerable benefits with the addition of a RM. Improvements in speech recognition were observed for all participants using RM systems, including those with relatively mild hearing loss. HASPI modelling reliably predicted the speech perception difficulties experienced.

Tone-burst elicited auditory brainstem responses in full-term and pre-term infants.

OBJECTIVE: To investigate the reliability of tone-burst auditory brainstem response (TB-ABR) latencies and thresholds in pre-term and full-term infants. DESIGN: TB-ABRs to 500 Hz and 4000 Hz tone-burst stimuli were recorded at two-week intervals over the first six weeks of life in a group of full-term infants (40-46 weeks gestational age [GA]) and over ten weeks (36-46 weeks gestation) in a group of preterm infants. Linear mixed model analyses evaluated within-subject changes and the effects of the subject group, age at assessment, and stimulus frequency on ABR latency and threshold. STUDY SAMPLE: Twenty-four infants participated. Nine were full-term (GA: 39-41 weeks) and fifteen were healthy pre-term (GA: 28-34 weeks) at birth. RESULTS: TB-ABR wave V latencies at 70 dBnHL decreased throughout the study (p < 0.001) in pre-term babies for both test frequencies by approximately 0.5 ms. There were, however, no group or GA (at birth) effects indicating that response latency normalized in these children by the due date. Similarly, TB-ABR threshold levels in the premature group were elevated (p = 0.001) by approximately 5 dB in pre-term evaluation but were equivalent to those of full-term participants in the post-term assessment period. CONCLUSIONS: In healthy, pre-term infants, tone-burst ABR testing is reliable from 36 weeks gestation.

Remediation of Perceptual Deficits in Progressive Auditory Neuropathy: A Case Study.

BACKGROUND: Auditory neuropathy (AN) is a hearing disorder that affects neural activity in the VIIIth cranial nerve and central auditory pathways. Progressive forms have been reported in a number of neurodegenerative diseases and may occur as a result of both the deafferentiation and desynchronisation of neuronal processes. The purpose of this study was to describe changes in auditory function over time in a patient with axonal neuropathy and to explore the effect of auditory intervention. METHODS: We tracked auditory function in a child with progressive AN associated with Charcot-Marie-Tooth (Type 2C) disease, evaluating hearing levels, auditory-evoked potentials, and perceptual abilities over a 3-year period. Furthermore, we explored the effect of auditory intervention on everyday listening and neuroplastic development. RESULTS: While sound detection thresholds remained constant throughout, both electrophysiologic and behavioural evidence suggested auditory neural degeneration over the course of the study. Auditory brainstem response amplitudes were reduced, and perception of auditory timing cues worsened over time. Functional hearing ability (speech perception in noise) also deteriorated through the first 1.5 years of study until the child was fitted with a "remote-microphone" listening device, which subsequently improved binaural processing and restored speech perception ability to normal levels. CONCLUSIONS: Despite the deterioration of auditory neural function consistent with peripheral axonopathy, sustained experience with the remote-microphone listening system appeared to produce neuroplastic changes, which improved the patient's everyday listening ability-even when not wearing the device.

The reliability of remote diagnostic hearing assessment in school-entry-aged children.

OBJECTIVE: To explore the feasibility of remote diagnostic hearing testing within schools, for school-entry aged children (4-7 years). DESIGN: A prospective cross-sectional comparative study design was used to establish the reliability of remote hearing assessment by comparing traditional face-to-face pure tone audiometry (PTA) with remote PTA, traditional otoscopy with remote video otoscopy and interpretation of tympanograms in-person with remote analysis. STUDY SAMPLE: 464 school-entry year level children from 18 schools. RESULTS: Air conduction thresholds established by remote testing were within a clinically acceptable range of ±10 dB HL from traditional thresholds in 98% of cases at 1 kHz and 97.8% at 4 kHz. Bone conduction thresholds varied by ≤10 dB HL in 100% of cases at 1 kHz and 95.7% at 4 kHz. Remote otoscopy and tympanometry interpretation had 78.6% agreement (moderate; κ = 0.6) and 92.2% agreement (almost perfect; κ = 0.9), respectively. CONCLUSIONS: We found there to be good reliability between face-to-face PTA and remote PTA performed within the school environment. Furthermore, assessment of the outer and middle ear via video otoscopy and remote tympanometry classification were both viable. Remote diagnostic hearing tests in schools can extend reach of paediatric services in rural areas.

Vestibular function and balance performance in children with sensorineural hearing loss.

OBJECTIVE: Balance difficulties are common in children with sensorineural hearing loss (SNHL). For some of these children, concomitant vestibular deficits may impact postural control. This study aimed to explore vestibular function, functional balance and postural control, and the relationship between these measures in children with SNHL. DESIGN: Cross-sectional study quantifying peripheral vestibular function (vestibular evoked myogenic potentials [VEMP], video head impulse test), functional balance (Bruininks-Oseretsky Test of Motor Proficiency [BOT]) and postural control (static posturography with modified sensory inputs). The relationship between the degree of vestibular impairment, functional balance and postural control was explored. STUDY SAMPLE: Eleven with SNHL, and 11 with normal sound detection (NSD) between 5 and 12 years of age. RESULTS: Children with SNHL had varying degrees of vestibular dysfunction and differences in overall balance performance. Across all children, greater degrees of vestibular impairment were associated with significantly poorer functional balance and postural control performance for complex standing conditions (BOT percentile rank p = 0.001; compliant surface eyes open [EO]: p = 0.027; compliant surface eyes closed: p = 0.048). CONCLUSIONS: Vestibular dysfunction in children with SNHL was variable. Vestibular impairment predicted poorer functional balance performance and postural control abilities, including differences in postural sway patterns.

Interviews with musicians with hearing aids.

Objectives: Musicians who wear hearing aids are a unique subset of hearing-impaired individuals. There are a number of issues musicians experience with hearing aids, making effective hearing rehabilitation a challenge. Research suggests hearing aid satisfaction in musicians is lower partly due to their advanced listening skills, however, qualitative research addressing musicians who wear hearing aids for music is scarce. The current study aimed to record the barriers encountered by musicians who wear hearing aids when playing their instrument/singing, listening to recorded music and listening to live music.Design: Professional musicians who wear hearing aids were interviewed. Participants were questioned about their experiences with hearing loss and hearing aids, with particular emphasis on experiences listening to recorded and live music, and playing or performing music with the hearing aids.Study Sample: Eight professional musicians were interviewed, using a semi-structured interview style, with a question and prompt guide.Results: Thematic analysis revealed three main themes in the data: the musicians' journey, communication, and flexibility/adjustability.Conclusions: The results have implications for future research into specific fitting parameters for hearing aids for musicians (particularly for music performance), the need for evidence-based rehabilitation programs for musicians with hearing loss, and the need for a glossary of terms to assist communication between Audiologists and musicians.

The effect of classroom environment on literacy development.

The physical characteristics of a child's learning environment can affect health, wellbeing and educational progress. Here we investigate the effect of classroom setting on academic progress in 7-10-year-old students comparing reading development in "open-plan" (multiple class groups located within one physical space) and "enclosed-plan" (one class group per space) environments. All learning conditions (class group, teaching personnel, etc.) were held constant throughout, while physical environment was alternated term-by-term using a portable, sound-treated dividing wall. One hundred and ninety-six students underwent academic, cognitive and auditory assessment at baseline and 146 of these were available for repeat assessment at the completion of 3 school terms, allowing within-child changes across an academic year to be calculated. Reading fluency development (change in words read-per-minute) was greater for the enclosed-classroom phases (P < 0.001; 95%CI 3.7, 10.0) and the children who showed the greatest condition difference (i.e. slower rate of development in the open-plan) were those with the worst speech perception in noise and/or poorest attention skills. These findings highlight the important role classroom setting plays in the academic development of young students.

Auditory neuropathy in mice and humans with Friedreich ataxia.

OBJECTIVE: Recent studies have found that human Friedreich ataxia patients have dysfunction of transmission in the auditory neural pathways. Here, we characterize hearing deficits in a mouse model of Friedreich ataxia and compare these to a clinical population. METHODS: Sixteen mice with a C57BL/6 background were evaluated. Eight were YG8Pook/J animals (Friedreich ataxia phenotype) and eight wild-type mice served as controls. Auditory function was assessed between ages 6 and 12 months using otoacoustic emissions and auditory steady-state responses. At study end, motor deficit was assessed using Rotorod testing and inner ear tissue was examined. Thirty-seven individuals with Friedreich ataxia underwent auditory steady-state evoked potential assessment and response amplitudes were compared with functional hearing ability (speech perception-in-noise) and disease status was measured by the Friedreich Ataxia Rating Scale. RESULTS: The YG8Pook/J mice showed anatomic and functional abnormality. While otoacoustic emission responses from the cochlear hair cells were mildly affected, auditory steady-state responses showed exaggerated amplitude reductions as the animals aged with Friedreich ataxia mice showing a 50-60% decrease compared to controls who showed only a 20-25% reduction (F(2,94) = 17.90, p < 0.00). Furthermore, the YG8Pook/J mice had fewer surviving spiral ganglion neurons, indicating greater degeneration of the auditory nerve. Neuronal density was 20-25% lower depending on cochlear region (F(1, 30) = 45.02, p < 0.001). In human participants, auditory steady-state response amplitudes were correlated with both Consonant-Nucleus-Consonant word scores and Friedreich Ataxia Rating Scale score. INTERPRETATION: This study found degenerative changes in auditory structure and function in YG8Pook/J mice, indicating that auditory measures in these animals may provide a model for testing Friedreich ataxia treatments. In addition, auditory steady-state response findings in a clinical population suggested that these scalp-recorded potentials may serve as an objective biomarker for disease progress in affected individuals.

The Assistive Benefits of Remote Microphone Technology for Normal Hearing Children With Listening Difficulties.

OBJECTIVES: Children often present with listening difficulties (LiD) but with normal sound detection thresholds. These children are susceptible to learning challenges, and struggle with the suboptimal acoustics of standard classrooms. Remote microphone technology (RMT) is one way to improve the listening environment. The aim of this study was to determine the assistive potential of RMT for speech identification and attention skills in children with LiD, and to investigate whether the benefits obtained by these children were greater than for those with no listening concerns. DESIGN: A total of 28 children with LiD and 10 control participants with no listening concerns aged 6 to 12 years were included in this study. Children attended two laboratory-based testing sessions, where their speech intelligibility and attention skills were behaviorally assessed with and without the use of RMT. RESULTS: There were significant improvements in speech identification and attention skills when RMT was used. For the LiD group, use of the devices improved speech intelligibility to being comparable or better than control abilities without RMT. Auditory attention scores also improved from being poorer than controls without RMT to comparable to control performance with device assistance. CONCLUSIONS: Use of RMT was found to have a positive effect on both speech intelligibility and attention. RMT should be considered a viable option for addressing common behavioral symptoms of LiD, including for the many children that present with concerns of inattentiveness.

Acoustic change complex for assessing speech discrimination in normal-hearing and hearing-impaired infants.

OBJECTIVE: This study examined (1) the utility of a clinical system to record acoustic change complex (ACC, an event-related potential recorded by electroencephalography) for assessing speech discrimination in infants, and (2) the relationship between ACC and functional performance in real life. METHODS: Participants included 115 infants (43 normal-hearing, 72 hearing-impaired), aged 3-12 months. ACCs were recorded using [szs], [uiu], and a spectral rippled noise high-pass filtered at 2 kHz as stimuli. Assessments were conducted at age 3-6 months and at 7-12 months. Functional performance was evaluated using a parent-report questionnaire, and correlations with ACC were examined. RESULTS: The rates of onset and ACC responses of normal-hearing infants were not significantly different from those of aided infants with mild or moderate hearing loss but were significantly higher than those with severe loss. On average, response rates measured at 3-6 months were not significantly different from those at 7-12 months. Higher rates of ACC responses were significantly associated with better functional performance. CONCLUSIONS: ACCs demonstrated auditory capacity for discrimination in infants by 3-6 months. This capacity was positively related to real-life functional performance. SIGNIFICANCE: ACCs can be used to evaluate the effectiveness of amplification and monitor development in aided hearing-impaired infants.

Evaluation of a game-based hearing screening program for identifying hearing loss in primary school-aged children.

OBJECTIVES: To evaluate a tablet-based hearing screening game in primary school aged children. To examine the prevalence of middle/outer ear pathology, hearing loss and spatial processing disorder in primary school aged children. DESIGN: The automated hearing test Sound Scouts was used as a screening tool, which measures hearing abnormalities through tests of speech-in-quiet/noise and tone-in-noise. Children who failed the screenings underwent follow up testing with pure tone audiometry, tympanometry, otoscopy, and the Listening in Spatialised Noise-Sentences test. Results of each test were compared to measure efficacy. STUDY SAMPLE: 1256 children aged 4-13 years from 8 primary schools. RESULTS: 111 children (8.84%) presented with evidence of middle/outer ear pathologies. 21 children (1.67%) had hearing loss in at least one ear. 30 children (2.52%) were diagnosed with spatial processing disorder. False positive rate was 5.01%, indicating that a relatively small proportion of the children who failed the screenings were subsequently shown to have normal auditory function. CONCLUSIONS: A game based program testing sound detection and binaural speech processing can be effective in detecting undiagnosed hearing deficits, in large format school-based hearing screenings. Prevalence of hearing abnormalities in Victorian primary school aged children were established, highlighting the value of school hearing screening programs.

Increased rate of listening difficulties in autistic children.

INTRODUCTION: Auditory challenges are both common and disruptive for autistic children and evidence suggests that listening difficulties may be linked to academic underachievement (Ashburner, Ziviani & Rodger, 2008). Such deficits may also contribute to issues with attention, behavior, and communication (Ashburner et al., 2008; Riccio, Cohen, Garrison & Smith, 2005). The present study aims to summarize the auditory challenges of autistic children with normal pure-tone hearing thresholds, and perceived listening difficulties, seen at auditory-ASD clinics in the US and Australia. METHODS: Data were compiled on a comprehensive, auditory-focused test battery in a large clinical sample of school-age autistic children with normal pure-tone hearing to date (N = 71, 6-14 years). Measures included a parent-reported auditory sensory processing questionnaire and tests of speech recognition in noise, binaural integration, attention, auditory memory and listening comprehension. Individual test performance was compared to normative data from children with no listening difficulties. RESULTS: Over 40% of patients exhibited significantly reduced speech recognition in noise and abnormal dichotic integration that were not attributed to deficits in attention. The majority of patients (86%) performed abnormally on at least one auditory measure, suggesting that functional auditory issues can exist in autistic patients despite normal pure-tone sensitivity. CONCLUSION: Including functional listening measures during audiological evaluations may improve clinicians' ability to detect and manage the auditory challenges impacting this population. Learner Outcomes: 1) Readers will be able to describe the auditory difficulties experienced by some autistic patients (ASD). 2) Readers will be able to describe clinical measures potentially useful for detecting listening difficulties in high-functioning autistic children.

A randomized controlled trial of remote microphone listening devices to treat auditory deficits in children with neurofibromatosis type 1.

BACKGROUND: A high proportion of patients with neurofibromatosis type 1 (NF1) present with functional hearing deficiency as a result of neural abnormality in the late auditory brainstem. METHODS: In this randomized, two-period crossover study, we investigated the hypothesis that remote-microphone listening devices can ameliorate hearing and communication deficits in affected school-aged children (7-17 years). Speech perception ability in background noise was evaluated in device-active and inactive conditions using the CNC-word test. Participants were then randomized to one of two treatment sequences: (1) inactive device for two weeks (placebo), followed by active device use for two weeks, or (2) active device for 2 weeks, followed by inactive device for 2 weeks. Listening and communication ratings (LIFE-R Questionnaire) were obtained at baseline and at the end of each treatment phase. RESULTS: Each participant demonstrated functional hearing benefits with remote-microphone use. All showed a speech perception in noise increase when the device was activated with a mean phoneme-score difference of 16.4% (p < 0.001) and reported improved listening/communication abilities in the school classroom (mean difference: 23.4%; p = 0.017). DISCUSSION: Conventional hearing aids are typically ineffective as a treatment for auditory neural dysfunction, making sounds louder, but not clearer for affected individuals. In this study, we demonstrate that remote-microphone technologies are acceptable/tolerable in pediatric patients with NF1 and can ameliorate their hearing deficits. CONCLUSION: Remote-microphone listening systems offer a viable treatment option for children with auditory deficits associated with NF1.

Auditory Dysfunction Among Individuals With Neurofibromatosis Type 1.

Importance: Neurofibromatosis type 1 (NF1) affects hearing through disruption of central auditory processing. The mechanisms, functional severity, and management implications are unclear. Objective: To investigate auditory neural dysfunction and its perceptual consequences in individuals with NF1. Design, Setting, and Participants: This case-control study included children and adults with NF1 and control participants matched on age, sex, and hearing level. Patients were recruited through specialist neurofibromatosis and neurogenetic outpatient clinics between April and September 2019. An evaluation of auditory neural activity, monaural/binaural processing, and functional hearing was conducted. Diffusion-weighted magnetic resonance imaging (MRI) data were collected from a subset of participants (10 children with NF1 and 10 matched control participants) and evaluated using a fixel-based analysis of apparent fiber density. Main Outcomes and Measures: Type and severity of auditory dysfunction evaluated via laboratory testing and questionnaire data. Results: A total of 44 participants (18 [41%] female individuals) with NF1 with a mean (SD) age of 16.9 (10.7) years and 44 control participants (18 [41%] female individuals) with a mean (SD) age of 17.2 (10.2) years were included in the study. Overall, 11 participants (25%) with NF1 presented with evidence of auditory neural dysfunction, including absent, delayed, or low amplitude electrophysiological responses from the auditory nerve and/or brainstem, compared with 1 participant (2%) in the control group (odds ratio [OR], 13.03; 95% CI, 1.59-106.95). Furthermore, 14 participants (32%) with NF1 showed clinically abnormal speech perception in background noise compared with 1 participant (2%) in the control group (OR, 20.07; 95% CI, 2.50-160.89). Analysis of diffusion-weighted MRI data of participants with NF1 showed significantly lower apparent fiber density within the ascending auditory brainstem pathways. The regions identified corresponded to the neural dysfunction measured using electrophysiological assessment. Conclusions and Relevance: The findings of this case-control study could represent new neurobiological and clinical features of NF1. Auditory dysfunction severe enough to impede developmental progress in children and restrict communication in older participants is a common neurobiological feature of the disorder.

Fiber-Specific Changes in White Matter Microstructure in Individuals With X-Linked Auditory Neuropathy.

OBJECTIVES: Auditory neuropathy (AN) is the term used to describe a group of hearing disorders, in which the hearing impairment occurs as a result of abnormal auditory nerve function. While our understanding of this condition has advanced significantly over recent years, the ability to determine the site of lesion and the extent of dysfunction in affected individuals remains a challenge. To this end, we investigated potential axonal degeneration in the white matter tracts of the brainstem in individuals with X-linked AN. We hypothesized that individuals with X-linked AN would show focal degeneration within the VIII nerve and/or auditory brainstem tracts, and the degree of degeneration would correlate with the extent of auditory perceptual impairment. DESIGN: This was achieved using a higher-order diffusion magnetic resonance imaging (dMRI)-based quantitative measure called apparent fiber density as obtained from a technique called single-shell 3-tissue constrained spherical deconvolution and analyzed with the fixel-based analysis framework. Eleven subjects with genetically confirmed X-linked AN and 11 controls with normal hearing were assessed using behavioral and objective auditory measures. dMRI data were also collected for each participant. RESULTS: Fixel-based analysis of the brainstem region showed that subjects with X-linked AN had significantly lower apparent fiber density in the VIII nerve compared with controls, consistent with axonal degeneration in this region. Subsequent analysis of the auditory brainstem tracts specifically showed that degeneration was also significant in these structures overall. The apparent fiber density findings were supported by objective measures of auditory function, such as auditory brainstem responses, electrocochleography, and otoacoustic emissions, which showed VIII nerve activity was severely disrupted in X-linked AN subjects while cochlear sensory hair cell function was relatively unaffected. Moreover, apparent fiber density results were significantly correlated with temporal processing ability (gap detection task) in affected subjects, suggesting that the degree of VIII nerve degeneration may impact the ability to resolve temporal aspects of an acoustic signal. Auditory assessments of sound detection, speech perception, and the processing of binaural cues were also significantly poorer in the X-linked AN group compared with the controls with normal hearing. CONCLUSIONS: The results of this study suggest that the dMRI-based measure of apparent fiber density may provide a useful adjunct to existing auditory assessments in the characterization of the site of lesion and extent of dysfunction in individuals with AN. Additionally, the ability to determine the degree of degeneration has the potential to guide rehabilitation strategies in the future.

The frequency-following response as an assessment of spatial processing.

Objective: It is important to detect children with difficulties distinguishing speech-in-noise early. Prompt identification may be assisted by an evoked potential. The aims of the present study were: 1) to evaluate the frequency-following response (FFR) as a measure of binaural processing and spatial listening and, 2) to investigate the relationship between the FFR and a behavioural measure of binaural processing and spatial listening. Design: A single group, repeated measures design. The FFR was recorded in two different spatial conditions and amplitudes compared to spatial listening ability. Study Sample: Thirty-two children (aged 6.0 to 13.1 years) with a range of spatial processing abilities as measured behaviourally using the Listening in Spatialised Noise Sentences test (LiSN-S). Results: FFR waveforms were elicited using speech-like stimuli in co-located and separated conditions. A significant (p≤0.005) spatial advantage effect was observed with larger amplitudes in the separated condition. No correlations were observed between FFR amplitude and LiSN-S results. Conclusions: The FFR shows promise as a measure of binaural processing and spatial listening, but could be measuring different processes to those measured by the LiSN-S.

Review: Using diffusion-weighted magnetic resonance imaging techniques to explore the microstructure and connectivity of subcortical white matter tracts in the human auditory system.

Since its inception 30 years ago, diffusion-weighted magnetic resonance imaging (dMRI) has advanced to become a common component of routine clinical MRI examinations. Diffusion-weighted magnetic resonance offers a way to measure anisotropic diffusion in-vivo, which has led to the development of techniques capable of characterising the orientation of diffusion within living tissue. These modelling techniques can be used to investigate the microstructure and connectivity of white matter tracts within the human brain. Such techniques have been used to study many neural networks within the human body. There is, however, a notable paucity of research utilising dMRI techniques to investigate the white matter tracts of the auditory brainstem. In this review we provide a brief introduction to the basic principles of dMRI analysis and consider some of the difficulties associated with applying dMRI techniques to study the auditory pathways of the brainstem. We also consider aspects of current dMRI methodologies relevant to the auditory brainstem to inform future research in this area.

Wireless binaural hearing aid technology for telephone use and listening in wind noise.

OBJECTIVE: To assess the speech perception benefits of binaural streaming technology for bilateral hearing aid users in two difficult listening conditions. DESIGN: Two studies were conducted to compare hearing aid processing features relating to telephone use and wind noise. Speech perception testing was conducted in four different experimental conditions in each study. STUDY SAMPLE: Ten bilaterally-aided children in each study. RESULTS: Significant improvements in speech perception were obtained with a wireless feature for telephone use. Significant speech perception benefits were also obtained with wireless hearing aid features when listening to speech in simulated wind noise. CONCLUSIONS: Binaural signal processing algorithms can significantly improve speech perception for bilateral hearing aid users in challenging listening situations.