Central Auditory Development Research Articles

Exploring the relation between the central auditory processing functions and language development among Arabic-speaking children with attention deficit hyperactivity disorder

Abstract Background Debate still exists on the effect of central auditory processing disorder (CAPD) on the language of children with attention deficit hyperactive disorder (ADHD). This study aimed to explore the deficits of the central auditory processing (CAP) functions and their relation to language development and ADHD symptoms in 30 Egyptian Arabic-speaking children with ADHD between 4 and ≤ 7 years old. ADHD symptoms were rated by Conners’ Parent Rating Scale–Revised. Language development was assessed by the Modified Pre-school Language Scale (PLS) 4th edition, the Arabic version, and the Egyptian Arabic Pragmatic Language Test. CAP functions were tested by the Pediatric Speech Intelligibility (PSI) test (Arabic version). Results Sixty percent of the ADHD children had comorbid CAPD with predominance among ADHD children of combined type. There was a significant positive correlation between all PSI subtests assessing the monotonic auditory closure and dichotic auditory separation abilities in both ears and the language ages by the modified PLS-4. There was also a significant positive correlation between scores of the Egyptian Arabic Pragmatic Language Test (EAPLT) and the monotonic auditory closure ability in both ears and auditory separation ability in the right ear only.There was a non-significant mild difference in scores of the modified PLS-4 in favor of the ADHD children with normal CAP functions. Conclusion Not all children with ADHD have central auditory processing disorder as both ADHD and CAPD are independent disorders. Better central auditory processing functions are associated with well-developed language and higher pragmatic skills in ADHD children.

Features of Cognitive Ability and Central Auditory Processing of Preschool Children With Minimal and Mild Hearing Loss.

This study aimed to investigate the current status of cognitive development and central auditory processing development of preschool children with minimal and mild hearing loss (MMHL) in Nanjing, China. We recruited 34 children with MMHL and 45 children with normal hearing (NH). They completed a series of tests, including cognitive tests (i.e., Wechsler Preschool and Primary Scale of Intelligence and Continuous Performance Test), behavioral auditory tests (speech-in-noise [SIN] test and frequency pattern test), and objective electrophysiological audiometry (speech-evoked auditory brainstem response and cortical auditory evoked potential). In addition, teacher evaluations and demographic information and questionnaires completed by parents were collected. Regarding cognitive ability, statistical differences in the verbal comprehensive index, full-scale intelligence quotient, and abnormal rate of attention test score were found between the MMHL group and the NH group. The children with MMHL performed poorer on the SIN test than the children with NH. As for the auditory electrophysiology of the two groups, the latency and amplitude of some waves of the speech-evoked auditory brainstem response and cortical auditory evoked potential were statistically different between the two groups. We attempted to explore the relationship between some key indicators of auditory processing and some key indicators of cognitive development. Children with MMHL are already at increased developmental risk as early as preschool. They are more likely to have problems with attention and verbal comprehension than children with NH. This condition is not compensated with increasing age during the preschool years. The results suggest a possible relationship between the risk of cognitive deficit and divergence of auditory processing. https://doi.org/10.23641/asha.22670473.

Delayed Cochlear Implantation in Children: A Parental Survey

Background: Untreated childhood hearing loss can adversely affect speech and language development as well as academic, social, emotional, and behavioral development. Early cochlear implantation before the age of 4 years, within the critical period for central auditory development, was found to be crucial in reducing the negative impact of auditory deprivation and appears to provide better outcomes than late implantation.
 aim: The aim of this study was to determine the reasons behind late cochlear implantation in children with congenital severe to profound sensorineural hearing loss.
 Methods: A retrospective study was conducted on all cases who received cochlear implants at Specialty Surgical Center, Benghazi, Libya between October 2017 and June 2021. Patients' medical records were reviewed and demographic and clinical data were collected. Children with other disabilities, and post-lingual and post-meningitis implantees were excluded from the study. Information about the reasons for the delay in receiving cochlear implants was obtained over the phone from parents whose children underwent cochlear implant surgery beyond the age of 4 years.
 Results: A total of 74 children were included, 38 boys and 36 girls. The mean age at implantation was 47 months. Forty-one percent (41%) of children were implanted after 4 years of age. Two-thirds of these children live outside Benghazi. Most of the children had at least one risk factor for hearing loss. The majority of parents reported more than one reason for the delayed implantation.
 Conclusion: It is found that parent decision-making for cochlear implantation is difficult and affected by many factors, including their personal beliefs (denial, social stigma and fear of surgery), lack of awareness about the existence of cochlear implant technology, and financial constraints. It is recommended that a national newborn hearing screening program is established for early detection and intervention and cost-effectiveness.

Alterations of structural and functional connectivity in profound sensorineural hearing loss infants within an early sensitive period: A combined DTI and fMRI study

Due to heightened level of neuroplasticity, there is a sensitive period (2–4 years after birth) that exists for optimal central auditory development. Using diffusion tensor imaging combined with resting-state functional connectivity (rsFC) analysis, this study directly investigates the structural connectivity alterations of the whole brain white matter (WM) and the functional reorganization of the auditory network in infants with sensorineural hearing loss (SNHL) during the early sensitive period. 46 bilateral profound SNHL infants prior to cochlear implantation (mean age, 17.59 months) and 33 healthy controls (mean age, 18.55 months) were included in the analysis. Compared with controls, SNHL infants showed widespread WM alterations, including bilateral superior longitudinal fasciculus, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, right corticospinal tract, posterior thalamic radiation and left uncinate fasciculus. Moreover, SNHL infants demonstrated increased rsFC between left/right primary auditory cortex seeds and right insula and superior temporal gyrus. In conclusion, this study suggests that SNHL in the early sensitive period is associated with diffuse WM alterations that mainly affect the auditory and language pathways. Furthermore, increased rsFC in areas mainly associated with auditory and language networks may potentially reflect reorganization and compensatory activation in response to auditory deprivation during the early sensitive period.

Behavioral and neural spatial acuity can be persistently reduced by early temporary hearing loss

Children experiencing asymmetrical hearing early in life, typically due to conductive hearing loss (CHL) associated with ear infection, often display reduced behavioral spatial acuity that persists long after hearing is restored, suggesting abnormal central auditory development. We hypothesized that persistent CHL disrupts the experience-dependent fine-tuning of binaural hearing necessary in the developing auditory system to support normal behavioral spatial acuity. Using an animal model (the guinea pig), we found that chronic unilateral CHL during development (induced by an earplug) caused the brain to generate a less precise representation of auditory space. When the hearing loss was reversed by simply removing the earplug, both the spatial acuity of single neurons in the inferior colliculus and behavioral performance in a simple sound location acuity task were ~threefold worse than animals that had not worn earplugs, as if the sense of auditory space had been blurred. Overall, the results suggest that experiencing even temporary hearing loss during early development can persistently alter the normal maturation of the auditory brain circuits that are necessary to support good spatial acuity. Thus, the maladaptive plasticity in these circuits due to temporary hearing loss during development can place limitations on spatial acuity in adulthood. [Support: R01-DC011555, T32-DC012280, F31-DC014219.]

Influence of malnutrition on the development of the central nervous system of malnourished children

Introduction: Protein-caloric malnutrition is a public health concern in certain areas of the Brazil. It can affect growth, the auditory nervous system development and, consequently, the cognition. This study compared the Brainstem Auditory Evoked Potential (BAEP) between malnourished and eutrophic children.Methods: A total of 111 children, aged 0–60 months, were examined: 57 were malnourished, according to the World Health Organization criteria, and 54 were normo-nourished. All the subjects underwent otorhinolaryngological evaluations and had acoustic immittance and transient evoked otoacoustic emissions within the normal range. The BAEP responses to click and tone burst stimuli were recorded at intensities of 80, 60, 40, and 30 dBNA.Results: We observed that latencies of I, III, and V waves and interpeaks III–V at 80 dBNA with click stimuli were significantly higher in all malnourished children when compared to those in the eutrophic children, as was the I–V interval in the 0- to 24-month group. The V-wave latencies at those intensities were also significantly higher in malnourished children.Conclusions: Malnourished children presented changes in BAEP characterized by delayed wave latency and interpeak intervals when compared to eutrophic children, suggesting alterations in both peripheral and central auditory pathways development and maturation.

Early temporary asymmetrical hearing impairs behavioral and neural sensitivity to sound location

Children experiencing asymmetrical hearing early in life often display binaural hearing impairments that persist long after symmetric hearing is restored, suggesting abnormal central auditory development. Here, we test the hypothesis that abnormal neural coding of the interaural level difference (ILD) cue to sound location, resulting from asymmetrical hearing during development, underlies the hearing impairments. Guinea pigs were reared for 8 weeks from birth with a unilateral conductive hearing loss (CHL via earplug). After earplug removal we measured behavioral spatial acuity, the binaural interaction component (BIC) of the auditory brainstem response (ABR), and sensitivity to ILDs in auditory midbrain neurons (inferior colliculus, IC). Animals raised with asymmetric hearing displayed worse spatial acuity (~2x worse) for high-pass noise compared to age-matched controls, suggesting impaired sensitivity to ILDs. Physiologically, animals displayed abnormal BICs of the ABR indicating altered binaural proces...

Cortical auditory evoked potentials in congenital hearing impaired children with cochlear implants

By investigating the auditory cortical evoked potential in congenital hearing impaired children with cochlear implants, the association between central auditory development and the age of implantation was studied. P1-N1-P2 were recorded in 110 profound hearing impaired children, aged from 12 to 80 months old and being implanted with cochlear implants before the age of 5 years. Their implant using time ranged from just at the switch-on to 48 months. The stimuli were /m/, /t/, /g/, presented at 65 dB SPL in sound field. The presence rate of each wave was obtained and the relationship between P1 latency and implant age, the time of speech processor switch-on were analyzed. The presence rate of P1, N1 and P2 was 66.4%, 15.5% and 12.7%, respectively. The presence of P1 was significantly higher than that of N1(χ(2)=228.542, P=0.00)and P2(χ(2)=257.438, P=0.00). There was no significant difference of P1 presence rate elicited by /m/, /t/ and /g/(64.1%, 66.9% and 68.3%, χ(2)=0.589, P=0.75). There existed no significant difference either among P1 latency(P=0.22)or amplitude(P=0.09) elicited by /m/, /t/ and /g/. There was significant difference between the implant age before and after 42-month-old regarding the proportion that entered the age-appropriate normal P1 latency range(P=0.02). No significant difference was found among groups of implant using time of 1, 2, 3 and 4 years in aspect of the proportion that entered the age-appropriate normal P1 latency range(P=1.00). Compared with implanted after the age of 42-month-old children with prelingual hearing impairment younger than 5 years old, the ones implanted before 42-month-old have more chance for normal development for central auditory system. Once implanted before 42-month-old, the cortical auditory system restored its normal development as early as 1 year after implantation.

Temporary unilateral hearing loss during development impairs behavioral and neural sensitivity to interaural level difference cues for sound localization

Children who experience persistent conductive hearing loss (CHL) early in life often display binaural hearing impairments that persist long after CHL is resolved, suggesting abnormal central auditory development. Abnormal sensitivity to interaural level differences (ILDs) is particularly likely as a CHL (such as an ear infection) can attenuate sound in the affected ear by >30 dB, dramatically distorting ILD cues. Here, we quantified the effects of unilateral CHL on (1) behavioral spatial acuity and (2) neural information processing of ILD cues in the guinea pig auditory midbrain (inferior colliculus, IC) using the mathematical framework of Fisher information (FI). Animals raised with unilateral CHL displayed larger minimum audible angles for high-pass noise compared to age-matched controls, suggesting impaired ILD sensitivity. Based on acoustic directional transfer function measurements, ILD discrimination thresholds were elevated by ~3–6 dB. Following behavior, extracellular recordings were made in the I...

Music-based rehabilitation in cochlear implant users: Insights from brain-plasticity research

Music-based rehabilitation in cochlear implant users: Insights from brain-plasticity research

Central auditory development in children with hearing impairment: Clinical relevance of the P1 CAEP biomarker in children with multiple disabilities

Objective: We review the development and plasticity of the central auditory pathways in infants and children with hearing loss who are fitted with cochlear implants (CIs). Secondly, we describe case studies demonstrating the clinical utility of the P1 central auditory evoked potential (CAEP) for evaluating cortical auditory maturation in the rapidly increasing number of cochlear-implanted children who have multiple disabilities. Study design: Children who receive CIs provide a platform to examine the trajectories of deprivation-induced and experience-dependent plasticity in the central auditory system. We review the evidence for, and time-limits of, sensitive periods for cortical auditory maturation framing an optimal period for cochlear implantation. Finally, we evaluate the use of the P1 biomarker as an objective assessment tool in the special case of children with multiple disabilities. Results: The P1 response was useful in assessing central auditory maturation in patients with CHARGE association, ANSD, and Pallister-Killian syndrome concomitant with hearing loss. Conclusion: The presence of coexisting disabilities in addition to hearing loss poses unique challenges regarding both pre-intervention evaluation and post-intervention rehabilitation for children with multiple disabilities. When combined with a standard audiological test battery, the P1 CAEP biomarker has a useful role in objectively evaluating the maturation of central auditory pathways to determine the effectiveness of various intervention strategies in hearing-impaired children with multiple disabilities.

Central auditory development after long-term cochlear implant use

ObjectiveWe aimed to determine whether long-term cortical auditory development is altered or delayed in children using cochlear implants relative to their normal hearing peers. We hypothesized that cortical development in children using unilateral cochlear implants follows a normal trajectory with long-term auditory input when the duration of bilateral auditory deprivation in childhood is limited. MethodsElectrically-evoked cortical responses were recorded in 79 children who received one cochlear implant within 2.03±1.36years of bilateral deafness and had up to ∼16years of time-in-sound experience, and in 58 peers with normal hearing. Amplitude differences between the responses from children using cochlear implants and with normal hearing were calculated between 0 and 300ms. ResultsResponses from cochlear implant users remain different from those of their normal hearing peers. These differences decreased over time, but were not eliminated even after 10years of time-in-sound. Specifically, the P1–N1–P2–N2 complex, typical of a normally mature response, began to emerge by 10years of time-in-sound experience, but the amplitudes of peaks P2 and N2 became abnormally large. ConclusionMature-like cortical responses emerge in children after long-term unilateral cochlear implant use, however, differences from normal persist. SignificanceMaturation of cortical responses with long-term cochlear implant use potentially underlies functional improvements in hearing. Persistent differences from normal could reflect an increase in attention or multi-sensory processing during listening.

Linguistic multi-feature paradigm as an eligible measure of central auditory processing and novelty detection in 2-year-old children

This study evaluated whether the linguistic multi-feature paradigm with five types of speech-sound changes and novel sounds is an eligible neurophysiologic measure of central auditory processing in toddlers. Participants were 18 typically developing 2-year-old children. Syllable stimuli elicited significant obligatory responses and syllable changes significant MMN (mismatch negativity) which suggests that toddlers can discriminate auditory features from alternating speech-sound stream. The MMNs were lateralized similarly as found earlier in adults. Furthermore, novel sounds elicited a significant novelty P3 response. Thus, the linguistic multi-feature paradigm with novel sounds is feasible for the concurrent investigation of the different stages of central auditory processing in 2-year-old children, ranging from pre-attentive encoding and discrimination of stimuli to attentional mechanisms in speech-like research compositions. As a conclusion, this time-efficient paradigm can be applied to investigating central auditory development and impairments in toddlers in whom developmental changes of speech-related cortical functions and language are rapid.

Selective Tracing of Auditory Fibers in the Avian Embryonic Vestibulocochlear Nerve

The embryonic chick is a widely used model for the study of peripheral and central ganglion cell projections. In the auditory system, selective labeling of auditory axons within the VIIIth cranial nerve would enhance the study of central auditory circuit development. This approach is challenging because multiple sensory organs of the inner ear contribute to the VIIIth nerve (1). Moreover, markers that reliably distinguish auditory versus vestibular groups of axons within the avian VIIIth nerve have yet to be identified. Auditory and vestibular pathways cannot be distinguished functionally in early embryos, as sensory-evoked responses are not present before the circuits are formed. Centrally projecting VIIIth nerve axons have been traced in some studies, but auditory axon labeling was accompanied by labeling from other VIIIth nerve components (2,3). Here, we describe a method for anterograde tracing from the acoustic ganglion to selectively label auditory axons within the developing VIIIth nerve. First, after partial dissection of the anterior cephalic region of an 8-day chick embryo immersed in oxygenated artificial cerebrospinal fluid, the cochlear duct is identified by anatomical landmarks. Next, a fine pulled glass micropipette is positioned to inject a small amount of rhodamine dextran amine into the duct and adjacent deep region where the acoustic ganglion cells are located. Within thirty minutes following the injection, auditory axons are traced centrally into the hindbrain and can later be visualized following histologic preparation. This method provides a useful tool for developmental studies of peripheral to central auditory circuit formation.

Speech perception and cortical auditory evoked potentials in cochlear implant users with auditory neuropathy spectrum disorders

ObjectiveTo characterize the P1 component of long latency auditory evoked potentials (LLAEPs) in cochlear implant users with auditory neuropathy spectrum disorder (ANSD) and determine firstly whether they correlate with speech perception performance and secondly whether they correlate with other variables related to cochlear implant use. MethodsThis study was conducted at the Center for Audiological Research at the University of São Paulo. The sample included 14 pediatric (4–11 years of age) cochlear implant users with ANSD, of both sexes, with profound prelingual hearing loss. Patients with hypoplasia or agenesis of the auditory nerve were excluded from the study. LLAEPs produced in response to speech stimuli were recorded using a Smart EP USB Jr. system. The subjects’ speech perception was evaluated using tests 5 and 6 of the Glendonald Auditory Screening Procedure (GASP). ResultsThe P1 component was detected in 12/14 (85.7%) children with ANSD. Latency of the P1 component correlated with duration of sensorial hearing deprivation (*p=0.007, r=0.7278), but not with duration of cochlear implant use. An analysis of groups assigned according to GASP performance (k-means clustering) revealed that aspects of prior central auditory system development reflected in the P1 component are related to behavioral auditory skills. ConclusionsIn children with ANSD using cochlear implants, the P1 component can serve as a marker of central auditory cortical development and a predictor of the implanted child's speech perception performance.

Age-related dissociation of sensory and decision-based auditory motion processing

Studies on the maturation of auditory motion processing in children have yielded inconsistent reports. The present study combines subjective and objective measurements to investigate how the auditory perceptual abilities of children change during development and whether these changes are paralleled by changes in the event-related brain potential (ERP). We employed the mismatch negativity (MMN) to determine maturational changes in the discrimination of interaural time differences (ITDs) that generate lateralized moving auditory percepts. MMNs were elicited in children, teenagers, and adults, using a small and a large ITD at stimulus offset with respect to each subject's discrimination threshold. In adults and teenagers large deviants elicited prominent MMNs, whereas small deviants at the behavioral threshold elicited only a marginal or no MMN. In contrast, pronounced MMNs for both deviant sizes were found in children. Behaviorally, however, most of the children showed higher discrimination thresholds than teens and adults. Although automatic ITD detection is functional, active discrimination is still limited in children. The lack of MMN deviance dependency in children suggests that unlike in teenagers and adults, neural signatures of automatic auditory motion processing do not mirror discrimination abilities. The study critically accounts for advanced understanding of children's central auditory development.

Current concepts in repair of aural atresia

To look at the current rationale behind surgical candidacy for aural atresia. In addition, we review recent technical aspects of the procedure, as it relates to outcomes. Traditionally, aural atresia repair has been mostly reserved for bilateral atresia patients or occasionally unilateral patients with ideal conditions. Repair has also typically followed microtia repair with cartilage reconstruction. Developing literature, however, shows that the critical period of central auditory development precedes the typical timing of repair, particularly after rib cartilage microtia reconstruction. Newer synthetic microtia repairs have allowed atresia repair prior to microtia repair to capture the developmental advantages of binaural hearing early in life. We also review recent data on the use of ossicular prostheses in atresia repair regarding audiologic outcomes and other techniques attributed to better outcomes. Atresia repair remains one of the most challenging otologic procedures. As techniques improve and we understand the developing auditory system, surgical criteria may shift, with more patients becoming candidates at a younger age.

Central Auditory Processing Development in Adolescents With and Without Learning Disabilities

Auditory processing deficit (APD) is estimated to affect 5% of school-age children and adolescents, and 30-50% of those diagnosed with learning problems. The diagnosis and indeed the existence of APD, however, remain controversial. One reason for this controversy is that the factors contributing to normal variations in auditory processing and its development are poorly understood. To address the developmental issue, we compared the performance of younger (14 yr/o) and older (18 yr/o) adolescents on frequency discrimination, backward masking detection and gap detection using an oddball paradigm. Older adolescents had lower backward masking thresholds compared with younger adolescents, but the prolonged development of thresholds was not accompanied by a corresponding increase in performance consistency. The distribution of thresholds on all three tasks did not differ between typically developing adolescents and those diagnosed with learning disabilities. A questionnaire designed to tap difficulties in daily listening situations also failed to differentiate the two groups. These findings suggest that basing the diagnosis of APD on tests conducted with the oddball procedure requires the establishment of norms from large and age specific samples. They also suggest that the development of auditory sensory acuity in the general population is longer than typically assumed.

Cortical development, plasticity and re-organization in children with cochlear implants

A basic tenet of developmental neurobiology is that certain areas of the cortex will re-organize, if appropriate stimulation is withheld for long periods. Stimulation must be delivered to a sensory system within a narrow window of time (a sensitive period) if that system is to develop normally. In this article, we will describe age cut-offs for a sensitive period for central auditory development in children who receive cochlear implants. We will review de-coupling and re-organization of cortical areas, which are presumed to underlie the end of the sensitive period in congenitally deaf humans and cats. Finally, we present two clinical cases which demonstrate the use of the P1 cortical auditory evoked potential as a biomarker for central auditory system development and re-organization in congenitally deaf children fitted with cochlear implants. Learning outcomes: Readers of this article should be able to (i) describe the importance of the sensitive period as it relates to development of central auditory pathways in children with cochlear implants; (ii) discuss the hypothesis of de-coupling of primary from higher-order auditory cortex as it relates to the end of the sensitive period; (iii) discuss cross-modal re-organization which may occur after long periods of auditory deprivation; and (iv) understand the use of the P1 response as a biomarker for development of central auditory pathways.

Auditory brainstem activity and development evoked by apical versus basal cochlear implant electrode stimulation in children

Objective The role of apical versus basal cochlear implant electrode stimulation on central auditory development was examined. We hypothesized that, in children with early onset deafness, auditory development evoked by basal electrode stimulation would differ from that evoked more apically. Methods Responses of the auditory nerve and brainstem, evoked by an apical and a basal implant electrode, were measured over the first year of cochlear implant use in 50 children with early onset severe to profound deafness who used hearing aids prior to implantation. Results Responses at initial stimulation were of larger amplitude and shorter latency when evoked by the apical electrode. No significant effects of residual hearing or age were found on initial response amplitudes or latencies. With implant use, responses evoked by both electrodes showed decreases in wave and interwave latencies reflecting decreased neural conduction time through the brainstem. Apical versus basal differences persisted with implant experience with one exception; eIII–eV interlatency differences decreased with implant use. Conclusions Acute stimulation shows prolongation of basally versus apically evoked auditory nerve and brainstem responses in children with severe to profound deafness. Interwave latencies reflecting neural conduction along the caudal and rostral portions of the brainstem decreased over the first year of implant use. Differences in neural conduction times evoked by apical versus basal electrode stimulation persisted in the caudal but not rostral brainstem. Significance Activity-dependent changes of the auditory brainstem occur in response to both apical and basal cochlear implant electrode stimulation.