A European perspective on auditory processing disorder-current knowledge and future research focus

Current notions of \u201chearing impairment,\u201d 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 \u201cAuditory Processing Disorder\u201d (APD) or \u201cCentral Auditory Processing Disorder\u201d 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 optimumdiagnosis 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

ICBEN review of research on the biological effects of noise 2011-2014

The mandate of the International Commission on Biological Effects of Noise (ICBEN) is to promote a high level of scientific research concerning all aspects of noise-induced effects on human beings and animals. In this review, ICBEN team chairs and co-chairs summarize relevant findings, publications, developments, and policies related to the biological effects of noise, with a focus on the period 2011-2014 and for the following topics: Noise-induced hearing loss; nonauditory effects of noise; effects of noise on performance and behavior; effects of noise on sleep; community response to noise; and interactions with other agents and contextual factors. Occupational settings and transport have been identified as the most prominent sources of noise that affect health. These reviews demonstrate that noise is a prevalent and often underestimated threat for both auditory and nonauditory health and that strategies for the prevention of noise and its associated negative health consequences are needed to promote public health

New trends in the prevention of occupational noise-induced hearing loss

Noise exposure during lifespan is one of the main causes of hearing loss. The highest risk of noise-induced hearing loss (NIHL) is related to exposures in the workplace, and affects about 7% of the population. Occupational NIHL is irreversible, thus its prevention must be considered a priority. Although current hearing conservation programs (HCPs) have proved to be very beneficial, the incidence of occupational NIHL is still high, reaching about 18% of overexposed workers. This paper reviews recent research on the effects of noise on hearing in pursuit of more effective methods for the prevention of occupational NIHL. The paper discusses the translational significance of noise-induced cochlear neuropathy, as recently shown in animals, and the concept of hidden hearing loss in relation to current NIHL damage risk criteria. The anticipated advantages of monitoring the incidents of the temporary threshold shift (TTS) in workers exposed to high levels of noise have been analyzed in regard to the preclinical diagnostics of NIHL, i.e., at the stage when hearing loss is still reversible. The challenges, such as introducing speech-in-noise audiometry and TTS computational predictive models into HCPs, have been discussed. Finally, the paper underscores the need to develop personalized medical guidelines for the prevention of NIHL and to account for several NIHL risk factors other than these included in the ISO 1999:2013 model. Implementing the steps mentioned above would presumably further reduce the incidence of occupational NIHL, as well as associated social costs

Noise-induced hearing loss

Noise-induced hearing loss (NIHL) still remains a problem in developed countries, despite reduced occupational noise exposure, strict standards for hearing protection and extensive public health awareness campaigns. Therefore NIHL continues to be the focus of noise research activities. This paper summarizes progress achieved recently in our knowledge of NIHL. It includes papers published between the years 2008-2011 (in English), which were identified by a literature search of accessible medical and other relevant databases. A substantial part of this research has been concerned with the risk of NIHL in the entertainment sector, particularly in professional, orchestral musicians. There are also constant concerns regarding noise exposure and hearing risk in "hard to control" occupations, such as farming and construction work. Although occupational noise has decreased since the early 1980s, the number of young people subject to social noise exposure has tripled. If the exposure limits from the Noise at Work Regulations are applied, discotheque music, rock concerts, as well as music from personal music players are associated with the risk of hearing loss in teenagers and young adults. Several recent research studies have increased the understanding of the pathomechanisms of acoustic trauma, the genetics of NIHL, as well as possible dietary and pharmacologic otoprotection in acoustic trauma. The results of these studies are very promising and offer grounds to expect that targeted therapies might help prevent the loss of sensory hair cells and protect the hearing of noise-exposed individuals. These studies emphasize the need to launch an improved noise exposure policy for hearing protection along with developing more efficient norms of NIHL risk assessment

Cochlear dysfunction is associated with styrene exposure in humans.

AIM:Occupational exposure to styrene has been shown to be associated with an increased probability of developing hearing loss. However, the sites of lesions in the auditory system in humans remain unknown. The aim of this study was to investigate the possible adverse effects of styrene exposure on the cochlea of human subjects. DESIGN:The hearing function of 98 styrene-exposed male workers from the glass fibre-reinforced plastics industry (mean concentration of 55 mg/m3) was evaluated bilaterally using pure-tone audiometry (1000-16000 Hz), distortion product otoacoustic emissions (DPOAEs), and auditory brainstem response (ABR). The results were compared to a group of 111 male workers exposed to noise (above 85 dBA) and 70 male white-collar workers exposed to neither noise nor solvents. Age and noise exposure levels were accounted for as confounding variables in all statistical models. RESULTS:Styrene exposure was significantly associated with poorer pure-tone thresholds (1-8 kHz), lower DPOAE amplitudes (5-6 kHz), and shorter wave V latencies in both ears compared to control-group subjects. Similar results were found among noise-exposed subjects. A further analysis with wave V latency showed that styrene-exposed subjects showed significantly shorter latencies than expected according to normative data. These results suggest that occupational exposure to styrene at moderate concentrations is associated with cochlear dysfunction, at least at high frequencies. DPOAEs may be considered a valuable diagnostic tool in hearing conservation programs in workers exposed to styrene

Temporal processing disorder associated with styrene exposure

Little evidence exists on the possible adverse effects of styrene on the central part of the auditory system. The present investigation aimed to study the possible association between styrene exposure and temporal processing abilities. Fifty-nine styrene-exposed subjects and 50 nonexposed control subjects were tested. Pure-tone audiometry (125–8000 Hz) and 3 temporal processing tests (gaps-in-noise, frequency pattern test and duration pattern test) were carried out. Significant differences between groups were found for most of the audiometric thresholds for both ears. ANCOVA analysis showed that styrene-exposed subjects had significantly poorer performances on the frequency and duration pattern tests than nonexposed subjects, when including hearing level and age as covariates. The results of the present research study suggest an association between styrene exposure and central auditory dysfunction characterized by a temporal processing disorder

Absence of short-term effects of UMTS exposure on the human auditory system

The aim of this study, which was performed in the framework of the European project EMFnEAR, was to investigate the potential effects of Universal Mobile Telecommunications System (UMTS, also known as 3G) exposure at a high specific absorption rate (SAR) on the human auditory system. Participants were healthy young adults with no hearing or ear disorders. Auditory function was assessed immediately before and after exposure to radiofrequency (RF) radiation, and only the exposed ear was tested. Tests for the assessment of auditory function were hearing threshold level (HTL), distortion product otoacoustic emissions (DPOAE), contralateral suppression of transiently evoked otoacoustic emission (CAS effect on TEOAE), and auditory evoked potentials (AEP). The exposure consisted of speech at a typical conversational level delivered via an earphone to one ear, plus genuine or sham RF-radiation exposure obtained by an exposure system based on a patch antenna and controlled by software. Results from 73 participants did not show any consistent pattern of effects on the auditory system after a 20-min UMTS exposure at 1947 MHz at a maximum SAR over 1 g of 1.75 W/kg at a position equivalent to the cochlea. Analysis entailed a double-blind comparison of genuine and sham exposure. It is concluded that short-term UMTS exposure at this relatively high SAR does not cause measurable immediate effects on the human auditory syste