The article presents a preliminary evaluation of occupational hearing loss risk in a group of farmers selected at random and exposed to a mean annual level of exposure to noise L(EX,8h) = 89.1 dB. The study covered 31 family farms carrying out mixed production (plant-animal), possessing arable land of the size 5-40 ha, and equipped with the basic mechanical equipment (tractors, agricultural mac...

The objective was to investigate the reliability and effects of age and noise on high-frequency hearing thresholds. A cross-sectional study was used involving 187 exposed and 52 non-industrial noise-exposed subjects selected randomly from noise-exposed and non-industrial noise-exposed subjects, respectively. Each subject was tested with both conventional-frequency (0.25-8 kHz) and high-frequenc...

A frequency-domain numerical model of brass instrument sound production is proposed as a tool to predict their brassiness, defined as the rate of spectral enrichment with increasing dynamic level. It is based on generalized Burger's equations dedicated to weakly nonlinear wave propagation in nonuniform ducts, and is an extension of previous work by Menguy and Gilbert [Acta Acustica 86, 798-810 ...

Somatosensory, visual and auditory cortical and brainstem evoked responses were obtained from 32 patients with severe head injury. A simple count of the number of waves present in the various responses provided the optimum method of analysing the data. The results of each cortical response, but not of the brainstem response, correlated with outcome, and a combined assessment gave the highest co...

Five groups of 10-day-old chicks were continuously exposed to either 500 or 1500 Hz pure tone at 125 dB for 4 or 12 h and killed 10 days later. The basilar papillae were fixed, embedded in plastic, sectioned, and hair cells were counted according to type: tall or short. Short hair cells were found to be more susceptible to acoustic overstimulation than tall hair cells. Further, the position of ...

The auditory epithelium in birds and mammals consists of a postmitotic population of hair cells and supporting cells. Unlike mammals, birds can regenerate their auditory epithelia after trauma. Recent evidence indicates that supporting cells undergo mitosis after acoustic trauma, suggesting that supporting cells may transdifferentiate into hair cells. The goals of this study were to 1) characte...

BACKGROUND Exposure to intense sound or high doses of aminoglycoside antibiotics can increase hearing thresholds, induce cochlear dysfunction, disrupt hair cell morphology and promote hair cell death, leading to permanent hearing loss. When the two insults are combined, synergistic ototoxicity occurs, exacerbating cochlear vulnerability to sound exposure. The underlying mechanism of this synerg...

It was found that intense pure-tones which damage hair cells in chicks, also result in damage to the tectorial membrane (TM). This study was designed to elucidate the effects of a second pure-tone insult on hair cells which survived a priming pure-tone exposure. Chicks were exposed to a pure-tone of 1.5 kHz at 124 dB SPL. Lesion was found in both TM and hair cells, but the area of damage to the...

An acute acoustic trauma (AAT) results when the unprotected ear is exposed to very high sound pressure levels, usually as the result of an industrial or milita~ accident. A study was performed to evaluate the effects of a corticosteroid (dexamethasone) on the hearing loss from a series of blast waves that would simulate an AAT. Groups of chinchillas were exposed individually to ten 160-dB peak ...

with the aim of identifying failure mechanism in oriented strand boards, failure behavior of wood strands under tensile load was investigated using acoustic emission technique. resinated and unresinated strands were arranged at top, middle and bottom section of the board before pressing. tensile and acoustic emission tests were performed simultaneously on treated and control samples. using tens...