Contralateral suppression of otoacoustic emissions in a clinical sample of children with auditory processing disorder.

OBJECTIVE: The suppression of evoked otoacoustic emissions (EOAE) may serve as a clinical tool to evaluate the medial olivocochlear (MOC) reflex, which is thought to aid speech discrimination (particularly in noise) by selectively inhibiting cochlear amplification. The present study aimed to determine if contralateral transient evoked otoacoustic emission (TEOAE) suppression was present in a clinical sample of children with listening difficulties with and without auditory processing disorder (APD). DESIGN: A three-group, repeated measure design was used. STUDY SAMPLE: Forty three children aged 8-14 years underwent an auditory processing assessment and were divided into three groups: children with reported listening difficulties with APD, children with reported listening difficulties without APD, and children with normal hearing. APD was defined as per British Society of Audiology. RESULTS: TEOAE suppression was present in all three participant groups. No significant group, age or ear effects were observed for TEOAE suppression in dB or as a normalised index. CONCLUSION: Contralateral TEOAE suppression method could not be used as a clinical tool to identify APD in this study's participating children and did not support the hypothesised link between reduced MOC function and general listening difficulties in background noise in children with or without APD.

Electrophysiological characteristics in children with listening difficulties, with or without auditory processing disorder.

Objective: To determine if the auditory middle latency responses (AMLR), auditory late latency response (ALLR) and auditory P300 were sensitive to auditory processing disorder (APD) and listening difficulties in children, and further to elucidate mechanisms regarding level of neurobiological problems in the central auditory nervous system. Design: Three-group, repeated measure design. Study sample: Forty-six children aged 8-14 years were divided into three groups: children with reported listening difficulties fulfilling APD diagnostic criteria, children with reported listening difficulties not fulfilling APD diagnostic criteria and normally hearing children. Results: AMLR Na latency and P300 latency and amplitude were sensitive to listening difficulties. No other auditory evoked potential (AEP) measures were sensitive to listening difficulties, and no AEP measures were sensitive to APD only. Moderate correlations were observed between P300 latency and amplitude and the behavioural AP measures of competing words, frequency patterns, duration patterns and dichotic digits. Conclusions: Impaired thalamo-cortical (bottom up) and neurocognitive function (top-down) may contribute to difficulties discriminating speech and non-speech sounds. Cognitive processes involved in conscious recognition, attention and discrimination of the acoustic characteristics of the stimuli could contribute to listening difficulties in general, and to APD in particular.

Normative data for diagnosing auditory processing disorder in Norwegian children aged 7-12 years.

OBJECTIVE: The main purpose of this research was to obtain normative data for auditory processing tests for Norwegian speaking children. DESIGN: Participants were administered routine audiological tests and an auditory processing test-battery consisting of Filtered Words, Competing Words, Dichotic Digits, Gaps In Noise, Duration- and Frequency Pattern, Binaural Masking Level Difference and HIST Speech in Noise test. A group of 10-year-old children were retested after two weeks. The effects ear, age and gender and the test-retest reliability were investigated. STUDY SAMPLE: There were 268 normal hearing children aged 7-12 years who participated in the study. RESULTS: Results revealed no differences between genders. The children showed improving performance by age on all tests, except from the Gaps In Noise and Binaural Masking Level Difference. As expected, the children showed a right ear advantage on dichotic speech tests that decreased with age. The test-retest reliability for the tests was good, with a small learning effect on the Filtered Words test. CONCLUSION: Normative data were established and the preferred tests for diagnosing Auditory Processing Disorder were suggested for Norwegian children aged 7-12 years.

Establishment of the Norwegian hearing register for children.

Introduction: The Norwegian Directorate of Health approved the Norwegian Hearing Register for Children in 2022. The main objective of the register is to improve the quality of treatment for children with permanent hearing loss, by measures, follow-ups and monitoring the quality and results of the health care system. Methods: Inclusion criteria are children who do not pass universal newborn hearing screening and/or children with permanent hearing loss <18 years of age. Hearing loss is defined as pure-tone audiometry threshold of (PTA4) > 20 dB in at least one ear. Data are registered at the Ear, Nose and Throat departments at inclusion and at follow-ups at the age of 3, 6, 10, and 15 years. The register collects information about the child within a holistic perspective. The key elements of the register are (a) data concerning newborn hearing screening; (b) data concerning hearing, medical information, hearing amplification and intervention (c) patient reported outcome measures registered by caregivers using three questionnaires; Pediatric Quality of Life Inventory, Strengths and Difficulties Questionnaire and Parents' Evaluation of Aural/Oral Performance of Children. Results: The register has established four quality indicators regarding newborn hearing screening and early intervention (a) the rate of false positive neonatal screens; (b) testing for congenital cytomegalovirus within 3 weeks of age for children who do not pass newborn hearing screening; (c) audiological evaluation to confirm the hearing status no later than 3 months of age and (d) initiated intervention within 3 months after confirmation of hearing status. Discussion: The register will include the total population of hearing impaired children over long time periods. Thus, the register enables each hospital to monitor their quality indicator scores continuously and compare them with national levels in real time. This facilitates and accelerates identification of improvement areas in the hospitals and will be an important contributor for quality improvement in NHS, diagnostics and hearing intervention for children in Norway. In addition, data from the register will be a unique source for research, and study designs with a long follow-up time can be applied.