Exploring the Differences Between an Immature and a Mature Human Auditory System Through Auditory Late Responses in Quiet and in Noise.

Children are disadvantaged compared to adults when they perceive speech in a noisy environment. Noise reduces their ability to extract and understand auditory information. Auditory-Evoked Late Responses (ALRs) offer insight into how the auditory system can process information in noise. This study investigated how noise, signal-to-noise ratio (SNR), and stimulus type affect ALRs in children and adults. Fifteen participants from each group with normal hearing were studied under various conditions. The findings revealed that both groups experienced delayed latencies and reduced amplitudes in noise but that children had fewer identifiable waves than adults. Babble noise had a significant impact on both groups, limiting the analysis to one condition: the /da/ stimulus at +10 dB SNR for the P1 wave. P1 amplitude was greater in quiet for children compared to adults, with no stimulus effect. Children generally exhibited longer latencies. N1 latency was longer in noise, with larger amplitudes in white noise compared to quiet for both groups. P2 latency was shorter with the verbal stimulus in quiet, with larger amplitudes in children than adults. N2 latency was shorter in quiet, with no amplitude differences between the groups. Overall, noise prolonged latencies and reduced amplitudes. Different noise types had varying impacts, with the eight-talker babble noise causing more disruption. Children's auditory system responded similarly to adults but may be more susceptible to noise. This research emphasizes the need to understand noise's impact on children's auditory development, given their exposure to noisy environments, requiring further exploration of noise parameters in children.

Screening for Auditory Processing Disorder in French-Speaking School-Age Children: A Pilot Study.

OBJECTIVES: A few clinical screening tools for auditory processing disorder (APD) are currently available. However, most of these tools are in English and cannot be used to screen individuals with a first language other than English. This study aimed to develop an APD screening test battery in French and to assess its psychometric properties in detecting school-age children at risk of APD. METHOD: Prior to their complete audiological APD assessment, 53 children (7-12 years old) were recruited from an audiology clinic. The APD assessment lasted between 2 and 3 hr, including 15-20 min for the screening test battery. The screening test battery was composed of four behavioral subtests and two questionnaires (parent and teacher). RESULTS: When combined, two among the four behavioral subtests showed a sensitivity of 100% and a specificity of 80%. CONCLUSION: The newly developed screening tool could help reduce the number of unnecessary APD assessments, therefore allowing early diagnosis in children with APD and increasing their chances of receiving adequate intervention.

Assessing Auditory Processing in Children with Listening Difficulties: A Pilot Study.

BACKGROUND: Auditory processing disorders (APD) may be one of the problems experienced by children with listening difficulties (LiD). The combination of auditory behavioural and electrophysiological tests could help to provide a better understanding of the abilities/disabilities of children with LiD. The current study aimed to quantify the auditory processing abilities and function in children with LiD. METHODS: Twenty children, ten with LiD (age = 8.46; SD = 1.39) and ten typically developing (TD) (age = 9.45; SD = 1.57) participated in this study. All children were evaluated with auditory processing tests as well as with attention and phonemic synthesis tasks. Electrophysiological measures were also conducted with click and speech auditory brainstem responses (ABR). RESULTS: Children with LiD performed significantly worse than TD children for most behavioural tasks, indicating shortcomings in functional auditory processing. Moreover, the click-ABR wave I amplitude was smaller, and the speech-ABR waves D and E latencies were longer for the LiD children compared to the results of TD children. No significant difference was found when evaluating neural correlates between groups. CONCLUSIONS: Combining behavioural testing with click-ABR and speech-ABR can highlight functional and neurophysiological deficiencies in children with learning and listening issues, especially at the brainstem level.

The development of auditory functions.

Typical development and maturation of the auditory system, at both the peripheral and central levels, is essential for the acquisition of speech, language, and auditory skills. The peripheral system generally encodes three basic parameters associated with auditory stimuli-time, frequency, and intensity. These acoustic cues are subsequently processed by the central auditory structures to reach and be perceived by the cerebral cortex. Observations of the human fetal and neonatal ear indicate that the peripheral auditory system is structurally and functionally adult-like at birth. In contrast, the central auditory system exhibits progressive anatomical and physiologic changes until early adulthood. Enriched experience with sound is fundamental and critical to auditory development. The absence of early and prolonged acoustic stimulation delays neuronal maturation, affecting the central auditory nervous system, in particular, and leading to atypical development. The present chapter reviews the various stages of development of the auditory system structures, especially the embryology of the human ear, before briefly presenting the trajectories of typical development of auditory abilities from infants to school-aged children.

Prenatal masculinization of the auditory system in infants: The MIREC-ID study.

Sex differences in inner-ear function are detectable in infants, notably through the measurement of otoacoustic emissions (OAEs). Prevailing theories posit that prenatal exposure to high levels of androgens in boys may weaken OAEs, and that this phenomenon may predominantly affect the right ear/left hemisphere (Geschwind-Galaburda (GG) hypothesis). Yet, actual tests of these models have been difficult to implement in humans. Here we examined the relationship between markers of fetal androgen exposure collected at birth (anogenital distances (AGD); penile length/width, areolar/scrotal/vulvar pigmentation) and at 6 months of age (2nd to 4th digit ratio (2D:4D)) with two types of OAEs, click-evoked OAEs (CEOAEs) and distortion-product OAEs (DPOAEs) (n = 49; 25 boys; 24 girls). We found that, in boys, scrotal pigmentation was inversely associated with the amplitude and reproducibility of CEOAEs in the right ear at 4 kHz, with trends also present in the same ear for mean CEOAE amplitude and CEOAE amplitude at 2 kHz. Penile length was inversely associated with the mean amplitude of DPOAEs in both the right and left ears, as well as with DPOAE amplitude in the right ear at 2 kHz and the reproducibility of CEOAEs in the left ear at 2.8 kHz. Finally, AGD-scrotum in boys was positively associated in boys with the amplitude of DPOAEs in the left ear at 2.8 kHz. Unexpectedly, there were no sex differences in the amplitude or reproducibility of OAEs, nor, in girls, any associations between androgenic markers and auditory function. Nonetheless, these findings, reported for the first time in a sample of human infants, support both the prenatal-androgen-exposure and GG models as explanations for the masculinization of auditory function in male infants.

Influence of external ear occlusion on food perception.

PURPOSE: The present study aimed to explore if food perception can be influenced by sound mastication level when the external ear canal was occluded. METHODS: Fifty-nine adults (38 women) with normal hearing, smell, and taste participated in the study. They tasted five crispy and five soft food items over two sessions: one with and one without an earplug inserted in the external ear canal. Participants were asked to rate freshness and taste of the food as well as their willingness to eat more of it and how much they usually like this kind of food. The sound pressure level related to the food mastication was recorded with a probe microphone placed in the external ear canal. RESULTS: Compared to the open ear canal condition, levels of the mastication sounds were higher when the participants had their ears occluded, as well as for crispy than for soft food. Regarding food freshness, food appreciation, and willingness to eat more of the same food, there was no significant difference concerning food type, ear condition, and sex. For soft foods, men rated their usual liking of this food higher when they were wearing ear plugs compared to the opened condition. CONCLUSION: Plugging the ear canals led to increased mastication sound levels. Participants did not seem to consider these additional acoustic cues when they rated food freshness, food appreciation, and willingness of eating the specific food. Only men seemed to take these cues into account when they rated their habit consumption of soft food.

Listening in noise training in children with auditory processing disorder: exploring group and individual data.

Purpose: The purpose of this study was to examine the impact of auditory training in noise on auditory behaviors and life habits in children with auditory processing disorder.Methods: Ten children with auditory processing disorder underwent an auditory training program in noise and six children with auditory processing disorder comprised a control group. Before and after training, participants were tested on sentence identification in noise and auditory evoked late latency responses. Participants teachers completed two questionnaires on children's auditory behaviors and life habits.Results: Participants were more tolerant to noise as the training sessions progressed. Significant between-group differences were found in P1 and N2 latency measures, independent of measurement time. The observed data trends suggest that some participants improved their performance on the sentence identification task in noise as well as on some electrophysiological parameters. No significant differences in questionnaire scores were found between groups or measurement times. However, one questionnaire showed significant between-group differences for certain questions.Conclusions: Listening in noise can improve with training for children with auditory processing disorder. However, this training program might be beneficial for some, but not all, children with auditory processing disorder. More data are needed to verify individual data trends.Implication for rehabilitationA structured program was developed to improve the ability of children with auditory processing disorder to listen in noise.Intervention can be beneficial for improving auditory behaviors in some children with auditory processing disorder.A limited number of questions on children's auditory behaviors asked to teachers appears to be more sensitive to intervention-related improvement compared to questions on life habits.

Tradução e adaptação de um software de treinamento da escuta no ruído para o português brasileiro / Translation and cross-cultural adaptation of a listening in noise auditory training software to brazilian portuguese

RESUMO Objetivo Traduzir e adaptar o software Logiciel d'Écoute dans le Bruit - LEB, verificar sua efetividade e jogabilidade em um grupo de escolares sem queixas auditivas e/ou de aprendizagem. Métodos A efetividade foi investigada por meio da análise do desempenho de dois grupos pareados, antes e depois do treinamento, no teste de fala comprimida. O grupo treinado (GT), constituído por 22 escolares, entre 9 a 10 anos de idade, recebeu treinamento com o software e o grupo controle (GC), composto por 20 escolares da mesma faixa etária, não recebeu nenhum tipo de estimulação. Após o treinamento, os sujeitos do GT responderam a uma avaliação qualitativa sobre o software. Resultados Os comandos foram compreendidos e executados com facilidade e eficácia. O questionário revelou que o LEB foi bem aceito e estimulante, proporcionando novos aprendizados. O GT apresentou evoluções significativas, em comparação ao GC. Conclusão O êxito na tradução, adaptação e jogabilidade do software fica evidenciado pelas mudanças observadas na habilidade de fechamento auditivo, sugerindo sua efetividade para treinamento da percepção da fala no ruído.

ABSTRACT Purpose To translate and to adapt the software "LEB", verify its effectiveness and playability in a group of students without hearing and / or learning complaints. Methods (I) Effectiveness was investigated by analyzing the performance of two paired groups before and after training in the compressed speech test. The trained group (TG), composed by 22 students aged 9 to 10 years old, received training with the software and the control group (CG), composed by 20 students of the same age, did not receive any type of stimulation; (II) after the training, the subjects of the TG responded to a qualitative evaluation about the software. Results The commands were understood and executed easily and effectively. The questionnaire revealed that LEB was well accepted and stimulating, providing new learning. The GT presented significant evolutions in comparison to the control group. Conclusions The success in the software's translation, adaptation and gameplay process is evidenced by the observed changes in the auditory closure ability, suggesting its effectiveness for training speech perception in the noise.

Deficit in Central Auditory Processing as a Biomarker of Pre-Clinical Alzheimer's Disease.

Prevention of dementia due to Alzheimer's disease (d/AD) requires interventions that slow the disease process prior to symptom onset. To develop such interventions, one needs metrics that assess pre-symptomatic disease progression. Familiar measures of progression include cerebrospinal fluid (CSF) biochemical and imaging analyses, as well as cognitive testing. Changes in the latter can sometimes be difficult to distinguish from effects of "normal" aging. A different approach involves testing of "central auditory processing" (CAP), which enables comprehension of auditory stimuli amidst a distracting background (e.g., conversation in a noisy bar or restaurant). Such comprehension is often impaired in d/AD. Similarly, effortful or diminished auditory comprehension is sometimes reported by cognitively healthy elders, raising the possibility that CAP deficit may be a marker of pre-symptomatic AD. In 187 cognitively and physically healthy members of the aging, AD family history-positive PREVENT-AD cohort, we therefore evaluated whether CAP deficits were associated with known markers of AD neurodegeneration. Such markers included CSF tau concentrations and magnetic resonance imaging volumetric and cortical thickness measures in key AD-related regions. Adjusting for age, sex, education, pure-tone hearing, and APOEɛ4 status, we observed a persistent relationship between CAP scores and CSF tau levels, entorhinal and hippocampal cortex volumes, cortical thickness, and deficits in cognition (Repeatable Battery for Assessment of Neuropsychological Status total score, and several of its index scales). These cross-sectional observations suggest that CAP may serve as a novel metric for pre-symptomatic AD pathogenesis. They are therefore being followed up longitudinally with larger samples.

Abnormalities in cortical auditory responses in children with central auditory processing disorder.

The main objective of the present study was to identify markers of neural deficits in children with central auditory processing disorder (CAPD) by measuring latency and amplitude of the auditory cortical responses and mismatch negativity (MMN) responses. Passive oddball paradigms were used with nonverbal and verbal stimuli to record cortical auditory-evoked potentials and MMN. Twenty-three children aged 9-12 participated in the study: 10 with normal hearing acuity as well as CAPD and 13 with normal hearing without CAPD. No significant group differences were observed for P1 latency and amplitude. Children with CAPD were observed to have significant N2 latency prolongation and amplitude reduction with nonverbal and verbal stimuli compared to children without CAPD. No significant group differences were observed for the MMN conditions. Moreover, electrode position affected the results in the same manner for both groups of children. The findings of the present study suggest that the N2 response could be a marker of neural deficits in children with CAPD. N2 results suggest that maturational factors or a different mechanism could be involved in processing auditory information at the central level for these children.

Life habits of school-aged children with specific language impairment as perceived by their parents and by school professionals.

PURPOSE: Describe social participation of a group of children with specific language impairment. METHOD: 26 parents of children with specific language impairment (SLI) aged from 5 to 13 years and 11 school professionals participated in the study. Data collection was performed with the adapted version for children aged from 5 to 13 years old of the Assessment of Life Habits (Fougeyrollas et al., 2001). The questionnaire encompasses 196 life habits, grouped in 12 dimensions: nutrition, fitness, personal care, communication, housing, mobility, responsibilities, interpersonal relationships, community life, education, work and recreation (Fougeyrollas, 2010). RESULTS: According to their parents and school professionals, children in this study carried out without difficulty life habits related to housing and mobility. However, they experienced difficulty with life habits related to interpersonal relationships, recreation and responsibilities, in addition to communication and education. CONCLUSIONS: Children with SLI are perceived by their parents and school professionals as having reduced social participation in many aspects of their daily life. Social participation should be considered as a major outcome when offering services in school to these children. This study proposes specific ways to help children with SLI.

Auditory event related potentials in children with peripheral hearing loss.

OBJECTIVE: The aim of the study was to investigate the neurophysiological responses in children with hearing loss. METHODS: Cortical auditory evoked potentials and Mismatch Negativity (MMN) Responses were recorded in 40 children, 9-12 years old: 12 with hearing loss, 12 with central auditory processing disorder (CAPD) and 16 with normal hearing. Passive oddball paradigms were used with nonverbal and verbal stimuli. RESULTS: For P1, no significant group differences were observed. A significant reduction in N2 amplitude with all stimuli was observed in the group of children with hearing loss compared to the results of those with normal hearing. N2 results did not reveal any significant differences between the group of children with hearing loss and the children with CAPD. MMN amplitude indicated a trend toward larger MMN amplitude among the group of children with hearing loss compared to the value of those of children with CAPD. CONCLUSIONS: Abnormal N2 characteristics could be a manifestation of a specific signature in children with hearing loss. This cortical response could be considered as a neurophysiologic marker of central auditory processing deficits in these children. SIGNIFICANCE: Results suggest maturational delays and/or deficits in central auditory processing in children with hearing loss.

Auditory temporal-organization abilities in school-age children with peripheral hearing loss.

PURPOSE: The objective was to assess auditory sequential organization (ASO) ability in children with and without hearing loss. METHOD: Forty children 9 to 12 years old participated in the study: 12 with sensory hearing loss (HL), 12 with central auditory processing disorder (CAPD), and 16 with normal hearing. They performed an ASO task in which they were asked to recall 2, 3, and 5 verbal and nonverbal stimuli with an interstimulus interval (ISI) of 425 ms as well as sequences of 2 elements with an ISI of 20 or 1,000 ms. RESULTS: No significant difference was found between the group of children with HL and the 2 other groups on nonverbal stimuli in all testing conditions. Regardless of ISI duration or number of elements in the sequence, children with HL had significantly fewer correct responses than children with normal hearing and children with CAPD for the verbal stimuli /ba/-/da/. Children with HL had significantly better performance than children with CAPD for the verbal a/-/da/ when the number of elements in the sequence varied. CONCLUSIONS: Children with sensory HL showed impaired ASO ability when recalling verbal /ba/-/da/. Results suggest that hearing loss can induce a specific signature when processing these verbal stimuli.

Cortical auditory evoked potentials in children with a hearing loss: a pilot study.

Objective. This study examined the patterns of neural activity in the central auditory system in children with hearing loss. Methods. Cortical potentials and mismatch responses (MMRs) were recorded from ten children aged between 9 and 10 years: five with hearing loss and five with normal hearing in passive oddball paradigms using verbal and nonverbal stimuli. Results. Results indicate a trend toward larger P1 amplitude, a significant reduction in amplitude, and latency of N2 in children with hearing loss compared to control. No significant group differences were observed for the majority of the MMRs conditions. Conclusions. Data suggest that the reduced auditory input affects the pattern of cortical-auditory-evoked potentials in children with a mild to moderately severe hearing loss. Results suggest maturational delays and/or deficits in central auditory processing in children with hearing loss, as indicated by the neurophysiological markers P1 and N2. In contrast, negative MMR data suggest that the amplification provided by the hearing aids could have allowed children with hearing loss to develop adequate discriminative abilities.

Assessing the development of binaural integration ability with the French dichotic digit test: Ecoute Dichotique de Chiffres.

PURPOSE: Binaural integration is assessed by dichotic listening tests. This study aimed to assess the development of binaural integration ability using a newly developed dichotic digit test in French. METHOD: Twenty-eight children with normal hearing sensitivity and binaural integration capacity, assessed with a dichotic listening word test, participated in the study. The children were divided into 3 groups: nine 6-year-olds, nine 9-year-olds, and ten 12-year-olds. They completed 4 subtests with earphones at normal conversational level. Three subtests consisted of 1, 2, and 3 different digit pairs, respectively, between 1 and 9 that were sent dichotically to the ears. The fourth subtest consisted of 4 digits, but only the 2 middle digits were sent dichotically. RESULTS: Performance improved significantly as a function of age and decreased with increasing number of digits to be repeated. All groups performed significantly better on digits presented in the right ear than the left ear, and on the digit rather than the word test. CONCLUSION: The new French dichotic digit test would be useful in assessing binaural integration in children. The 4 subtests make it suitable for inclusion in a test battery to assess central auditory processing in children and are an alternative, especially the fourth subtest, to the French version of the Staggered Spondaic Word Test (Rudmin & Normandin, 1983).

Random Gap Detection Test (RGDT) performance of individuals with central auditory processing disorders from 5 to 25 years of age.

OBJECTIVE: The aim of the present study was to assess the auditory temporal resolution ability in individuals with central auditory processing disorders, to examine the maturation effect and to investigate the relationship between the performance on a temporal resolution test with the performance on other central auditory tests. METHODS: Participants were divided in two groups: 131 with Central Auditory Processing Disorder and 94 with normal auditory processing. They had pure-tone air-conduction thresholds no poorer than 15 dB HL bilaterally, normal admittance measures and presence of acoustic reflexes. Also, they were assessed with a central auditory test battery. Participants who failed at least one or more tests were included in the Central Auditory Processing Disorder group and those in the control group obtained normal performance on all tests. Following the auditory processing assessment, the Random Gap Detection Test was administered to the participants. A three-way ANOVA was performed. Correlation analyses were also done between the four Random Gap Detection Test subtests data as well as between Random Gap Detection Test data and the other auditory processing test results. RESULTS: There was a significant difference between the age-group performances in children with and without Central Auditory Processing Disorder. Also, 48% of children with Central Auditory Processing Disorder failed the Random Gap Detection Test and the percentage decreased as a function of age. The highest percentage (86%) was found in the 5-6 year-old children. Furthermore, results revealed a strong significant correlation between the four Random Gap Detection Test subtests. There was a modest correlation between the Random Gap Detection Test results and the dichotic listening tests. No significant correlation was observed between the Random Gap Detection Test data and the results of the other tests in the battery. CONCLUSION: Random Gap Detection Test should not be administered to children younger than 7 years old because other reduced capacities might influence their performance. Also, Random Gap Detection Test assesses a specific auditory ability, different than the one evaluated with the other auditory tests. Finally, it is suggested to test individuals at only one frequency of the Random Gap Detection Test because results provide similar information than when assessing them on all subtests.

Speech perception in noise: exploring the effect of linguistic context in children with and without auditory processing disorder.

OBJECTIVE: The objective of this study was to investigate whether the speech perception problems in noise of children with auditory processing disorder (APD) stem from an auditory or a higher order dysfunction. DESIGN: A repeated measures design comparing the sentence key word recognition scores of children with APD and a control group was used. Four sentence lists from the Test de phrases dans le bruit (TPB) were presented with a babble masker at four different signal-to-noise ratios. The TPB is a Canadian French adaptation of the speech perception in noise test. STUDY SAMPLE: Ten participants between 9-12 years with APD participated in this study, as well as ten age- and gender-matched children with no sign of APD. RESULTS: Group analyses revealed that children with APD had poorer overall sentence key word recognition scores than the control group. Analysis of the difference scores between the high and low predictability sentences indicated that the benefit derived from linguistic context is similar between the groups. However, individual patterns of results revealed different profiles within the APD group. CONCLUSION: Further study using a larger sample is warranted to deepen our understanding of the nature of APD and identify characteristic profiles to enable better tailoring of therapeutic programs.

Auditory processing disorder and speech perception problems in noise: finding the underlying origin.

PURPOSE: A hallmark listening problem of individuals presenting with auditory processing disorder (APD) is their poor recognition of speech in noise. The underlying perceptual problem of the listening difficulties in unfavorable listening conditions is unknown. The objective of this article was to demonstrate theoretically how to determine whether the speech recognition problems are related to an auditory dysfunction, a language-based dysfunction, or a combination of both. METHOD: Tests such as the Speech Perception in Noise (SPIN) test allow the exploration of the auditory and language-based functions involved in speech perception in noise, which is not possible with most other speech-in-noise tests. Psychometric functions illustrating results from hypothetical groups of individuals with APD on the SPIN test are presented. This approach makes it possible to postulate about the origin of the speech perception problems in noise. CONCLUSION: APD is a complex and heterogeneous disorder for which the underlying deficit is currently unclear. Because of their design, SPIN-like tests can potentially be used to identify the nature of the deficits underlying problems with speech perception in noise for this population. A better understanding of the difficulties with speech perception in noise experienced by many listeners with APD should lead to more efficient intervention programs.

Peripheral hearing loss and auditory temporal ordering ability in children.

OBJECTIVE: The main objective of this study was to assess the influence of peripheral hearing loss (abnormal encoding of the auditory system) on auditory information processing. We examine the ability of children with and without hearing loss to correctly reproduce sequence blocks of acoustic stimuli that vary in type, number, and temporal ordering. METHODS: Twenty-six children between 8 and 12 years old, 13 with hearing loss and 13 without hearing loss, participated in the study. They performed an auditory temporal ordering task (auditory sequential organization task) by recalling two, three, and five verbal (/ba/-/da/and/a/-/da/) and nonverbal stimuli (acoustic transformation of /ba/-/da/) with a fixed interstimulus interval (ISI) of 425 ms. They also reproduced sequences of two elements with variables ISI, 20, and 1000 ms. RESULTS: Children with hearing loss had significantly lower correct responses than children with normal hearing for sequences of two, three, and five verbal stimuli with similar and complex acoustic features (/ba/-/da/), for an ISI of 425 ms. There was no significant difference in performance between children with hearing loss and their peers with normal hearing on nonverbal sequences or verbal sequences with different and complex acoustic features (/a/-/da/) when ISI was 425 ms. Furthermore, children with hearing loss performed significantly lower than their peers on the three groups of stimuli when ISI was 20 ms between two stimuli. CONCLUSION: Peripheral hearing loss can influence auditory information processing in the central auditory system.