Auditory processing disorders with and without central auditory discrimination deficits

Effect of concurrent exposure to noise and hand-transmitted vibration on auditory and cognitive attention under simulated work with construction tools

Objectives. This study aimed to investigate the effects of separate and concurrent exposure to occupational noise and hand-transmitted vibration (HTV) on auditory and cognitive attention. Methods. The experimental study was conducted with 40 construction workers who were exposed to noise (A-weighted equivalent sound pressure level of 90 dB) and to HTV (10 m/s2 at 31.5 Hz), and concurrent exposure to both for 30 min under simulated work with vibrating equipment used in construction. Cognitive performance aspects were then evaluated from each individual in two pre-exposure and post-exposure settings for each session. Results. The effect sizes of concurrent exposure (HTV + noise) and separate exposure to noise on auditory attention were very close (effect size = 0.648 and 0.626). The largest changes in the difference of response time in both types of attention (selective and divided attention) were related to the concurrent exposure scenario and then exposure to HTV, respectively. The highest effects for the correct response of selective and divided attention are related to concurrent exposure (HTV + noise) and then noise exposure, respectively. Conclusion. The HTV effect during concurrent exposure is hidden in auditory attention, and noise has the main effects. The divided attention was more affected than the selective attention in the different scenarios.

Understanding Auditory Processing Disorder: A Narrative Review

Auditory processing disorder (APD) is defined as difficulty in listening despite possessing hearing thresholds within the normal limit. Understanding rapid speech, following complex instructions, and listening in the existence of background noise are some of the difficulties in APD. APD has been observed in diverse clinical populations with suspected or diagnosed disorders, such as attention deficit-hyperactivity disorder, dyslexia, aphasia, and Alzheimer's disease; however, it should be differentiated from these disorders. Despite the research on APD, its awareness is limited, resulting in it often being undiagnosed. Therefore, improving the awareness and understanding of APD is important. The current paper aims to review the literature on APD with a focus on school-age children. The prevalence, etiology, screening, and diagnosis of APD are discussed along with correlated disorders, interpretation of tests, and management strategies.

A systematic review and metanalysis of questionnaires used for auditory processing screening and evaluation

The recognition of Auditory Processing Disorder (APD) as a distinct clinical condition that impacts hearing capacity and mental health has gained attention. Although pure tone audiometry is the gold standard for assessing hearing, it inadequately reflects everyday hearing abilities, especially in challenging acoustic environments. Deficits in speech perception in noise, a key aspect of APD, have been linked to an increased risk of dementia. The World Health Organization emphasizes the need for evaluating central auditory function in cases of mild hearing loss and normal audiometry results. Specific questionnaires play a crucial role in documenting and quantifying the difficulties faced by individuals with APD. Validated questionnaires such as the Children's Auditory Processing Performance Scale, the Fisher's Auditory Problems Checklist, and the Auditory Processing Domains Questionnaire are available for children, while questionnaires for adults include items related to auditory functions associated with APD. This systematic review and meta-analysis identified six questionnaires used for screening and evaluating APD with a total of 783 participants across 12 studies. The questionnaires exhibited differences in domains evaluated, scoring methods, and evaluation of listening in quiet and noise. Meta-analysis results demonstrated that individuals with APD consistently exhibited worse scores compared to healthy controls across all questionnaires. Additionally, comparisons with clinical control groups showed varying results. The study highlights (i) the importance of standardized questionnaires in identifying and assessing APD, aiding in its diagnosis and management, and (ii) the need to use sub-scores as well as overall scores of questionnaires to elaborate on specific hearing and listening situations. There is a need to develop more APD specific questionnaires for the adult population as well as for more focused research on APD diagnosed individuals to further establish the validity and reliability of these questionnaires.

The effect of ventilation tube insertion in central auditory processing disorders in children with otitis media with effusion

INTRODUCTION

Otitis media with effusion is one of the most common diseases among children. The purpose of this research is to investigate whether the resolvement of conductive hearing loss from the insertion of a ventilation tube also improves central auditory processing disorders in children with otitis media with effusion.

METHOD

In this cross-sectional study, 20 children between 6 and 12 years old were diagnosed with otitis media with effusion and 20 normal children were included in the study. The central auditory processing status was evaluated in all patients before ventilation tube insertion and after six months by Speech Discrimination Score, Speech Reception Threshold, Words-in-Noise, Speech in Noise, Consonant Vowel in Noise tests, and the results were compared.

RESULTS

The mean score of Speech Discrimination Score and Consonant Vowel in Noise tests in the control group were significantly higher than the patient group before ventilation tube insertion and after surgery, in the patient group, the mean scores increased significantly. The mean scores of the Speech Reception Threshold, Words-in-Noise, and Speech in Noise tests in the control group were significantly lower than the patient group before ventilation tube insertion and after the operation, in the patient group, the mean scores significantly decreased. After VT insertion, these tests were close to the control group.

CONCLUSION

Restituting normal hearing by ventilation tube treatment improves central auditory abilities as shown in speech reception, speech discrimination, the ability to hear, the ability to recognize monosyllabic words, and the power of speech in the presence of noise.

Sound localization with bilateral bone conduction devices

Purpose

To investigate sound localization in patients bilaterally fitted with bone conduction devices (BCDs). Additionally, clinically applicable methods to improve localization accuracy were explored.

Methods

Fifteen adults with bilaterally fitted percutaneous BCDs were included. At baseline, sound localization, (un)aided pure-tone thresholds, device use, speech, spatial and qualities of hearing scale (SSQ) and York hearing-related quality of life (YHRQL) questionnaire were measured. Settings to optimize sound localizing were added to the BCDs. At 1 month, sound localization was assessed again and localization was practiced with a series of sounds with visual feedback. At 3 months¸ localization performance, device use and questionnaire scores were determined again.

Results

At baseline, one patient with congenital hearing loss demonstrated near excellent localization performance and four other patients (three with congenital hearing loss) localized sounds (quite) accurately. Seven patients with acquired hearing loss were able to lateralize sounds, i.e. identify whether sounds were coming from the left or right side, but could not localize sounds accurately. Three patients (one with congenital hearing loss) could not even lateralize sounds correctly. SSQ scores were significantly higher at 3 months. Localization performance, device use and YHRQL scores were not significantly different between visits.

Conclusion

In this study, the majority of experienced bilateral BCD users could lateralize sounds and one third was able to localize sounds (quite) accurately. The localization performance was robust and stable over time. Although SSQ scores were increased at the last visit, optimizing device settings and a short practice session did not improve sound localization.

Development of central auditory processes in Polish children and adolescents at the age from 7 to 16 years

There are discrepancies in the literature regarding the course of central auditory processes (CAP) maturation in typically developing children and adolescents. The purpose of the study was to provide an overview of age – related improvement in CAP in Polish primary and secondary school students aged 7–16 years. 180 children/adolescents, subdivided into 9 age categories, and 20 adults (aged 18–24 years) performed the Dichotic Digit Test (DDT), Duration Pattern Test (DPT), Frequency Pattern Test (FPT), Gap Detection Test (GDT) and adaptive Speech-in-Noise (aSpN). The 12-year-olds was retested after w week. We found the age effects only for the DDT, DPT and FPT. In the right ear DDT the 7-year-olds performed more poorly than all groups ≥12. In the left ear DDT both 7- and 8-year-olds achieved less correct responses compared with the 13-, 14-, 15-year-olds and with the adults. The right ear advantage was greater in the 7-year-olds than in the 15-year-olds and adult group. At the age of 7 there was lower DPT and FPT scores than in all participants ≥13 whereas the 8-year-olds obtained less correct responses in the FPT than all age categories ≥12. Almost all groups (except for the 7-year-olds) performed better in the DPT than FPT. The test-retest reliability for all tests was satisfactory. The study demonstrated that different CAP have their own patterns of improvement with age and some of them are specific for the Polish population. The psychoacoustic battery may be useful in screening for CAP disorders in Poland.

Analyzing Longitudinal Data on Singing Voice Parameters of Boys and Girls Aged 8 to 12.5 and Possible Effects of a Music Pedagogical Intervention

OBJECTIVE

Controlled and randomized study to analyze longitudinal voice data of boys and girls aged 8-12.5, to describe their physiological development and to evaluate the influence of a one-year music pedagogical interventional program focused on the singing voice.

METHODS

Singing voice profiles of 116 children (52 boys, 64 girls) aged 8-12.5 years were collected longitudinally at the beginning and the end of the third school year and the end of the fourth school year. 64 of the 116 children received a music pedagogical program during their third school year (interventional group). Maximum and minimum voice intensity, highest and lowest frequency, maximum phonation time (MPT) and Jitter were investigated.

RESULTS

In two years' time highest frequency increased on average by 100.23 Hz from G1 up to A1 for boys and for girls. Lowest frequency decreased by 18.36Hz from Gis-1 to G-1 (boys: Gis-1-Fis-1; girls: A-1-G-1). There was no clinically relevant development of the intensity parameters for both sexes. However, after the interventional year, minimum voice intensity significantly decreased in the interventional group compared to the control group. The MPT increased by 2.41 seconds from 10.67 seconds up to 13.09 seconds in two years. Here the increase was higher for boys (+3.2 seconds) than for girls (+1.77 seconds). Jitter was found to be 0.84%-1.11%, showing no clinically relevant changes in two years.

CONCLUSION

To the best of our knowledge, for the first time this study presents longitudinal data on singing voice parameters of the voice range profile of boys and girls aged 8-12.5 years. While frequency and intensity parameters develop equally for boys and girls, the MPT is found to develop more distinctly within boys. A music pedagogical intervention of a small extent has a positive effect on the ability to sing as soft as possible.

Spectro-temporal modulation detection and its relation to speech perception in children with auditory processing disorder

OBJECTIVES

Poor speech perception in noise is one of the most common complaints reported for children with auditory processing disorder (APD). APD is defined as a deficit in perceptual processing of acoustic information in the auditory system in which decreased spectro-temporal resolution may also contribute. Since the recognition of spoken message in the context of other sounds, is based on the processing of auditory spectro-temporal modulations, the assessment of spectro-temporal modulations sensitivity can evaluate the listener's ability to retrieve and integrate speech segments covered by noise. Therefore, the purpose of this study was to examine spectro-temporal modulation (STM) detection and its relation to speech perception in children with APD and to compare the results with aged-matched normally developed children.

METHODS

35 children with APD and 32 normal hearing children (8-12 years old) were enrolled. In order to examine STM detection performance, six different STM stimulus conditions were employed using three different temporal modulation rates (4, 12 and 32 Hz) and two different spectral modulation densities (0.5 and 2.0 cycles/octave). Initially, the STM detection thresholds at these six STM stimulus conditions were measured in both groups and the results were compared. Thereafter, the relation between STM detection thresholds and speech perception tests, including consonant-vowel in noise and word in noise tests were assessed.

RESULTS

The STM sensitivity was poorer than normal for APD children at all STM stimulus conditions. Children with APD displayed significantly poorer STM detection thresholds than those of normally developed children (p < 0.05). Significant correlations were found between STM detection thresholds and speech perception in noise in both groups (p < 0.05).

CONCLUSION

The results suggest that the altered encoding of spectro-temporal acoustic cues in the auditory nervous system may be one of the underlying factors of reduced STM detection performance in children with APD. The present study may suggest that poor ability to extract STM cues in children with APD, can be an underlying factor for their listening problems in noise and poor speech perception in challenging situations.

Processamento auditivo (central) em escolares das séries iniciais de alfabetização

RESUMO Objetivo Caracterizar e comparar os testes comportamentais do processamento auditivo central de escolares das séries iniciais nas etapas, teste e reteste; e correlacionar as variáveis idade e gênero com os resultados destes testes. Método Estudo coorte, analítico, observacional, longitudinal e prospectivo; desenvolvido em uma escola da rede pública. Compuseram a amostra 36 escolares, subdivididos em dois grupos considerando a escolaridade: G1- 13 crianças do primeiro ano e G2- 23 crianças do segundo ano. Adotaram-se como critérios de inclusão: avaliação audiológica dentro dos padrões de normalidade e estar matriculado no primeiro ou segundo ano do ensino fundamental; e, como critérios de exclusão, presença de alterações neurológicas, cognitivas e comportamentais. A avaliação audiológica e a aplicação dos testes comportamentais do processamento auditivo central ocorreram em dois momentos distintos, com um intervalo de seis meses, denominados etapas teste e reteste. Resultados O teste com maior prevalência de alteração, em ambas as etapas e grupos, foi o Dicótico de Dígitos. Cabe ressaltar que nenhum escolar do G1 e alguns do G2 compreenderam o RGDT na etapa teste e que, mesmo após seis meses, esta dificuldade se manteve nos dois grupos. Na etapa reteste, notou-se melhora significante no desempenho dos escolares de ambos os grupos. Observou-se também, correlação entre a variável idade e o teste dicótico de dígitos na orelha esquerda, em ambas etapas. Conclusão Houve uma alta incidência de alteração nos testes e; se observou melhora no desempenho na etapa reteste, principalmente nos testes de localização sonora, dicótico de dígitos e RGDT.

Dichotic training in children with auditory processing disorder

OBJECTIVES

Several test batteries have been suggested for auditory processing disorder (APD) diagnosis. One of the important tests is dichotic listening tests. Significant ear asymmetry (usually right ear advantage) can be indicative of (APD). Two main trainings have been suggested for dichotic listening disorders: Differential Interaural Intensity Difference (DIID) and Dichotic Offset Training (DOT). The aim of the present study was comparing the efficacy of these two trainings in resolving dichotic listening disorders.

METHODS

12 children in the age range of 8 to 9 years old with APD were included (mean age 8.41 years old±0.51). They all had abnormal right ear advantage based on established age-appropriate norms for Farsi dichotic digit test. Then subjects were randomly divided into two groups (each contained 6 subjects): group 1 received DIID training (8.33 years old ±0.51) and group 2 received DOT training (8.50 years old±0.54).

RESULTS

Both trainings were effective in improvement of dichotic listening. There was a significant difference between two trainings with respect to the length of treatment (P-value≤0.001). DOT needed more training sessions (12.83±0.98 sessions) than DIID (21.16±0.75 sessions) to achieve the same amount of performance improvement.

CONCLUSION

Based on the present study it can be assumed that DOT might be a good replacement for DIID training in cases that DIID is not applicable and DIID candidacy conditions are not met. To generalize the results, studies with larger sample sizes are recommended.

Localization and Spatial Discrimination in Children and Adolescents with Moderate Sensorineural Hearing Loss Tested without Their Hearing Aids

The present study investigated two measures of spatial acoustic perception in children and adolescents with sensorineural hearing loss (SNHL) tested without their hearing aids and compared it to age-matched controls. Auditory localization was quantified by means of a sound source identification task and auditory spatial discrimination acuity by measuring minimum audible angles (MAA). Both low- and high-frequency noise bursts were employed in the tests to separately address spatial auditory processing based on interaural time and intensity differences. In SNHL children, localization (hit accuracy) was significantly reduced compared to normal-hearing children and intraindividual variability (dispersion) considerably increased. Given the respective impairments, the performance based on interaural time differences (low frequencies) was still better than that based on intensity differences (high frequencies). For MAA, age-matched comparisons yielded not only increased MAA values in SNHL children, but also no decrease with increasing age compared to normal-hearing children. Deficits in MAA were most apparent in the frontal azimuth. Thus, children with SNHL do not seem to benefit from frontal positions of the sound sources as do normal-hearing children. The results give an indication that the processing of spatial cues in SNHL children is restricted, which could also imply problems regarding speech understanding in challenging hearing situations.

Characteristics of Auditory Processing Disorders: A Systematic Review

PURPOSE

The purpose of this review article is to describe characteristics of auditory processing disorders (APD) by evaluating the literature in which children with suspected or diagnosed APD were compared with typically developing children and to determine whether APD must be regarded as a deficit specific to the auditory modality or as a multimodal deficit.

METHOD

Six electronic databases were searched for peer-reviewed studies investigating children with (suspected) APD in comparison with typically developing peers. Relevant studies were independently reviewed and appraised by 2 reviewers. Methodological quality was quantified using the American Speech-Language-Hearing Association's levels of evidence.

RESULTS

Fifty-three relevant studies were identified. Five studies were excluded because of weak internal validity. In total, 48 studies were included, of which only 1 was classified as having strong methodological quality. Significant dissimilarities were found between children referred with listening difficulties and controls. These differences relate to auditory and visual functioning, cognition, language, reading, and physiological and neuroimaging measures.

CONCLUSIONS

Methodological quality of most of the incorporated studies was rated moderate due to the heterogeneous groups of participants, inadequate descriptions of participants, and the omission of valid and reliable measurements. The listening difficulties of children with APD may be a consequence of cognitive, language, and attention issues rather than bottom-up auditory processing.

Decreased temporal precision of neuronal signaling as a candidate mechanism of auditory processing disorder

The sense of hearing is the fastest of our senses and provides the first all-or-none action potential in the auditory nerve in less than four milliseconds. Short stimulus evoked latencies and their minimal variability are hallmarks of auditory processing from spiral ganglia to cortex. Here, we review how even small changes in first spike latencies (FSL) and their variability (jitter) impact auditory temporal processing. We discuss a number of mouse models with degraded FSL/jitter whose mutations occur exclusively in the central auditory system and therefore might serve as candidates to investigate the cellular mechanisms underlying auditory processing disorders (APD).

Age-related changes in sound localisation ability

Auditory spatial processing is an important ability in everyday life and allows the processing of omnidirectional information. In this review, we report and compare data from psychoacoustic and electrophysiological experiments on sound localisation accuracy and auditory spatial discrimination in infants, children, and young and older adults. The ability to process auditory spatial information changes over lifetime: the perception of the acoustic space develops from an initially imprecise representation in infants and young children to a concise representation of spatial positions in young adults and the respective performance declines again in older adults. Localisation accuracy shows a strong deterioration in older adults, presumably due to declined processing of binaural temporal and monaural spectro-temporal cues. When compared to young adults, the thresholds for spatial discrimination were strongly elevated both in young children and older adults. Despite the consistency of the measured values the underlying causes for the impaired performance might be different: (1) the effect is due to reduced cognitive processing ability and is thus task-related; (2) the effect is due to reduced information about the auditory space and caused by declined processing in auditory brain stem circuits; and (3) the auditory space processing regime in young children is still undergoing developmental changes and the interrelation with spatial visual processing is not yet established. In conclusion, we argue that for studying auditory space processing over the life course, it is beneficial to investigate spatial discrimination ability instead of localisation accuracy because it more reliably indicates changes in the processing ability.

Medial efferent mechanisms in children with auditory processing disorders

Auditory processing disorder (APD) affects about 2–5% of children. However, the nature of this disorder is poorly understood. Children with APD typically have difficulties in complex listening situations. One mechanism thought to aid in listening-in-noise is the medial olivocochlear (MOC) inhibition. The purpose of this review was to critically analyze the published data on MOC inhibition in children with APD to determine whether the MOC efferents are involved in these individuals. The otoacoustic emission (OAE) methods used to assay MOC reflex were examined in the context of the current understanding of OAE generation mechanisms. Relevant literature suggests critical differences in the study population and OAE methods. Variables currently known to influence MOC reflex measurements, for example, middle-ear muscle reflexes or OAE signal-to-noise ratio, were not controlled in most studies. The use of potentially weaker OAE methods and the remarkable heterogeneity across studies does not allow for a definite conclusion whether or not the MOC reflex is altered in children with APD. Further carefully designed studies are needed to confirm the involvement of MOC efferents in APD. Knowledge of efferent functioning in children with APD would be mechanistically and clinically beneficial.