Parameters influencing auditory fatigue among professionals working in the amplified music sector: noise exposure and individual factors.

Objective: Hearing disorders are common among music professionals, as they are frequently exposed to sound levels exceeding 100 dB(A). By assessing auditory fatigue, situations that are deleterious for hearing could be identified, allowing the deployment of preventive measures before permanent impairment occurs. However, little is known about the factors contributing to auditory fatigue.

Temporary and Permanent Auditory Effects Associated with Occupational Coexposure to Low Levels of Noise and Solvents.

This study aimed to assess temporary and permanent auditory effects associated with occupational coexposure to low levels of noise and solvents. Cross-sectional study with 25 printing industry workers simultaneously exposed to low noise (<80 dBA TWA) and low levels of solvents. The control group consisted of 29 industry workers without the selected exposures.

Effects of co-exposure to CS and noise on hearing and balance in rats: continuous versus intermittent CS exposures.

Background: Carbon disulfide (CS) exacerbates the effect of noise on hearing, and disrupts the vestibular system. The goal of this study was to determine whether these effects are also observed with intermittent CS exposure.

Methods: Rats were exposed for 4 weeks (5 days/week, 6 h/day) to a band noise at 106 dB SPL either alone or combined with continuous (63 ppm or 250 ppm) or intermittent (15 min/h or 2 × 15 min/h at 250 ppm) CS.

Measuring the middle-ear reflex: A quantitative method to assess effects of industrial solvents on central auditory pathways.

Volatile organic solvents are frequently present in industrial atmospheres. Their lipophilic properties mean they quickly reach the brain following inhalation. Acute exposure to some solvents perturbs the middle ear reflex, which could jeopardize cochlear protection against loud noises.

Combined exposure to carbon disulfide and low-frequency noise reversibly affects vestibular function.

Chronic occupational exposure to carbon disulfide (CS2) has debilitating motor and sensory effects in humans, which can increase the risk of falls. Although no mention of vestibulotoxic effects is contained in the literature, epidemiological and experimental data suggest that CS2 could cause low-frequency hearing loss when associated with noise exposure. Low-frequency noise might also perturb the peripheral balance receptor through an as-yet unclear mechanism.

Auditory fatigue among call dispatchers working with headsets.

Objectives: To determine whether call center dispatchers wearing headsets are subject to auditory fatigue at the end of a work shift.

Material And Methods: Data was gathered at times when call centers were busiest. All call operators wore a headset for up to 12 h.

Continuous exposure to low-frequency noise and carbon disulfide: Combined effects on hearing.

Carbon disulfide (CS) is used in industry; it has been shown to have neurotoxic effects, causing central and distal axonopathies.However, it is not considered cochleotoxic as it does not affect hair cells in the organ of Corti, and the only auditory effects reported in the literature were confined to the low-frequency region. No reports on the effects of combined exposure to low-frequency noise and CS have been published to date.

Carbon disulfide potentiates the effects of impulse noise on the organ of Corti.

Occupational noise can damage workers' hearing, and the phenomenon is even more dangerous when noise is associated with an ototoxic solvent. Aromatic solvents are known to provoke chemical-induced hearing loss, but little is known about the effects on hearing of carbon disulfide (CS) when combined with noise. Co-exposure to CS and noise may have a harmful effect on hearing, but the mechanisms involved are not well understood.

Membrane fluidity does not explain how solvents act on the middle-ear reflex.

Some volatile aromatic solvents have similar or opposite effects to anesthetics in the central nervous system. Like for anesthetics, the mechanisms of action involved are currently the subject of debate. This paper presents an in vivo study to determine whether direct binding or effects on membrane fluidity best explain how solvents counterbalance anesthesia's depression of the middle-ear reflex (MER).

The tonotopicity of styrene-induced hearing loss depends on the associated noise spectrum.

The neuropharmacological and cochleotoxic effects of styrene can exacerbate the impact of noise on the peripheral auditory receptor. The mechanisms through which co-exposure to noise and styrene impairs hearing are complex as the slowly developing cochleotoxic process can be masked in the short-term by the rapid pharmacological effect on the central nervous system. The current investigation was therefore designed to delineate the auditory frequency range sensitive to noise, to styrene, and to noise and styrene combined.

Neuropharmacological and cochleotoxic effects of styrene. Consequences on noise exposures.

Occupational noise exposure can damage workers' hearing, particularly when combined with exposure to cochleotoxic chemicals such as styrene. Although styrene-induced cochlear impairments only become apparent after a long incubation period, the pharmacological impact of styrene on the central nervous system (CNS) can be rapidly measured by determining the threshold of the middle-ear acoustic reflex (MER) trigger. The aim of the study was to evaluate the effects of a noise (both continuous and impulse), and a low concentration of styrene [300ppm<(threshold limit value×10) safety factor] on the peripheral auditory receptor, and on the CNS in rats.

One-day measurement to assess the auditory risks encountered by noise-exposed workers.

Unlabelled: Noise is one of the most pervasive hazards in the workplace. Despite regulations and preventive measures, noise-induced hearing loss is common. The current reference test is pure-tone air-conduction audiometry (PTA), but this test cannot be used to detect early hearing loss.

Inhaled toluene can modulate the effects of anesthetics on the middle-ear acoustic reflex.

Toluene (Tol) is an organic solvent widely used in the industry. It is also abused as an inhaled solvent, and can have deleterious effects on hearing. Recently, it was demonstrated that Tol has both anticholinergic and antiglutamatergic effects, and that it also inhibits voltage-dependent Ca(2+) channels.

EchoScan: a new system to objectively assess peripheral hearing disorders.

Pure-tone air-conduction audiometry (PTA) is the reference clinical test used in Europe and the United States to measure the extent of hearing loss. It is a subjective, behavioral test, which measures thresholds of hearing sensations and perceptions based on patient responses to frequency-specific pure-tone stimuli. PTA can detect hearing problems due to cochlear or retro-cochlear impairment, without identifying the source of the problem.

Impact of noise or styrene exposure on the kinetics of presbycusis.

Presbycusis, or age-related hearing loss is a growing problem as the general population ages. In this longitudinal study, the influence of noise or styrene exposure on presbycusis was investigated in Brown Norway rats. Animals were exposed at 6 months of age, either to a band noise centered at 8 kHz at a Lex,8h = 85 dB (86.

Toluene effect on the olivocochlear reflex.

Animal studies have shown that toluene can cause hearing loss and can exacerbate the effects of noise by inhibiting the middle ear acoustic reflex. In this investigation, carried out in Long-Evans rats, the tensor tympani tendon was cutoff and the stapedius muscle was electrocoagulated in one or both middle ears. Rat hearing was evaluated by measuring cubic distortion otoacoustic emissions (2f1-f2; f1 = 8000 Hz; f2 = 9600 Hz; f1/f2 = 1.

Neuronal circuits involved in the middle-ear acoustic reflex.

Human and animal studies have shown that certain aromatic solvents such as toluene can cause hearing loss and can exacerbate the effects of noise. The latter effects might be due to a modification of responses of motoneurons controlling the middle-ear acoustic reflex. In the present investigation, the audition of Long-Evans rats was evaluated by measuring cubic (2f1 - f2) distortion otoacoustic emissions (f1 = 8000 Hz; f2 = 9600 Hz; f1/f2 = 1.

Toluene-induced hearing loss in the guinea pig.

Toluene is a high-production industrial solvent, which can disrupt the auditory system in rats. However, toluene-induced hearing loss is species dependent. For instance, despite long-lasting exposures to high concentrations of aromatic solvent, no study has yet succeeded in causing convincing hearing loss in the guinea pig.