[Diagnosis of auditory processing disorders in children]

Better education required for professionals in healthcare regarding auditory processing disorder

BACKGROUND

Global research has revealed inadequate levels of Auditory Processing Disorder (APD) awareness and knowledge among related professionals leading to neglect of this specific type of hearing impairment that is estimated to present in 50% of children with learning disabilities (dyslexia included) and more than 70% of adults with presbycusis or mild cognitive impairment.

PURPOSE

The aim of the current study was to record APD awareness and knowledge among professionals working in both Healthcare and Education sectors.

METHODS

A 36-question questionnaire was developed and addressed to medical doctors of different specialties (ENTs and non-ENTs), therapists (speech & language therapists, occupational therapists, psychologists), and educators (of both typical and special education). The questionnaire was sent to Professional Societies of interest as well as a University Rectorate where authors are affiliated, requesting the spreading to all members, and was also posted to related private groups in social media. Data concerning APD-training and knowledge were gathered from 522 questionnaires. Level of knowledge was recorded both subjectively (self-rating) and objectively (pre-defined scoring of items).

RESULTS

Analysis showed insufficient knowledge concerning APD among specialties. ENTs and/or therapists scored statistically significantly higher compared to other medical specialties and educators, while still lower than 50%. The current level of awareness on APD might negatively affect the way individuals with APD are addressed, all the way from referral to management. Levels of awareness and knowledge among professions which are related to APD either directly or indirectly can be further improved through formal education targeting bachelor, master and PhD programs of medical doctors, therapists and educators.

CONCLUSION

We are proposing the development of educational programs that target ENT doctors so that children and adults receive more elaborate services both diagnostically and from a rehabilitation point of view. This will improve quality of life and mental health.

Current audiological diagnostics

Today's audiological functional diagnostics is based on a variety of hearing tests, whose large number takes account of the variety of malfunctions of a complex sensory organ system and the necessity to examine it in a differentiated manner and at any age of life. The objective is to identify nature and origin of the hearing loss and to quantify its extent as far as necessary to dispose of the information needed to initiate the adequate medical (conservative or operational) treatment or the provision with technical hearing aids or prostheses. Moreover, audiometry provides the basis for the assessment of impairment and handicap as well as for the calculation of the degree of disability. In the present overview, the current state of the method inventory available for practical use is described, starting from basic diagnostics over to complex special techniques. The presentation is systematically grouped in subjective procedures, based on psychoacoustic exploration, and objective methods, based on physical measurements: preliminary hearing tests, pure tone threshold, suprathreshold processing of sound intensity, directional hearing, speech understanding in quiet and in noise, dichotic hearing, tympanogram, acoustic reflex, otoacoustic emissions and auditory evoked potentials. Apart from a few still existing gaps, this method inventory covers the whole spectrum of all clinically relevant functional deficits of the auditory system.

A European Perspective on Auditory Processing Disorder-Current Knowledge and Future Research Focus

Current notions of “hearing impairment,” as reflected in clinical audiological practice, do not acknowledge the needs of individuals who have normal hearing pure tone sensitivity but who experience auditory processing difficulties in everyday life that are indexed by reduced performance in other more sophisticated audiometric tests such as speech audiometry in noise or complex non-speech sound perception. This disorder, defined as “Auditory Processing Disorder” (APD) or “Central Auditory Processing Disorder” is classified in the current tenth version of the International Classification of diseases as H93.25 and in the forthcoming beta eleventh version. APDs may have detrimental effects on the affected individual, with low esteem, anxiety, and depression, and symptoms may remain into adulthood. These disorders may interfere with learning per se and with communication, social, emotional, and academic-work aspects of life. The objective of the present paper is to define a baseline European APD consensus formulated by experienced clinicians and researchers in this specific field of human auditory science. A secondary aim is to identify issues that future research needs to address in order to further clarify the nature of APD and thus assist in optimum diagnosis and evidence-based management. This European consensus presents the main symptoms, conditions, and specific medical history elements that should lead to auditory processing evaluation. Consensus on definition of the disorder, optimum diagnostic pathway, and appropriate management are highlighted alongside a perspective on future research focus.

[Acoustic reflexes of children with and without central auditory processing disorders]

BACKGROUND

According to international standards, determination of acoustic reflex thresholds (ART) is one of the established objective measurements in the diagnostic workup of central auditory processing disorders (CAPD). However, there is still no evidence for the significance of ART in CAPD diagnosis.

PATIENTS AND METHODS

This study tested 57 children with proven CAPD and 50 healthy children (control group) with regard to group differences in mean ART (sine tones or bandpass-filtered noise). Additionally, it was investigated whether there were group differences between the mean dissociations of ART for sine tones or bandpass filtered noise.

RESULTS

Neither ipsi- nor contralaterally were significant clinically relevant group differences (p < 0.050) between the mean ART of children with and without CAPD found. After Bonferroni correction, a significant group difference in the percentage of non-triggered reflexes was only observed with left-sided contralateral 2 kHz stimuli. Concerning the number of dissociations ≥20 dB, no significant group differences (p < 0.050) were detected either ipsi- or contralaterally (Fisher's test).

CONCLUSION

The results of the study seem to indicate no clinically relevant ability of ART measurements to distinguish between children with and without CAPD. This renders the benefit of ART measurements for CAPD diagnosis questionable.