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Results 401 - 450 of 646
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Wang J - - 1992
Changes in endocochlear potentials (EP), cochlear microphonics (CM), and compound action potentials (CAP) with noise exposure were investigated in guinea pigs. The animals were anesthetized and immobilized and exposed to white noise at intensities ranging from 105 to 125 dB. The negative EP (N-EP) was induced by anoxia and was ...
Hienz, Robert D.
An experimental analysis of the effects of low-dose ionizing radiation on sensory and motor function was conducted in baboons. Animals were trained using a reaction time procedure to respond to near-threshold acoustic and visual stimuli, and quantitative assessments were made of radiation-induced changes in absolute auditory and visual thresholds and ...
Furst M - - 1992
Comparison between changes that occur simultaneously on spontaneous otoacoustic emissions (SOAEs) and on other cochlear origin phenomena can contribute to the understanding of cochlear micromechanical activity. The temporary changes that arise after short noise exposure are investigated in the following paper. The effects of noise exposure on the threshold microstructure ...
Yamamura K - - 1992
The effects of noise exposure were studied in fifty-nine 4- to 5-week-old albino Hartley guinea pigs with normal hearing (body weight 250-300 g). The following experiments and results were carried out: exposure to 350 Hz pure tones at 115 dB for 40 h and exposure to 350 Hz tones at ...
SliwiƄska-Kowalska M - - 1992
It is well known that exposure to intense acoustic stimuli can induce permanent damage to the tissues of the inner ear. In this study the technique of ABR measurement and the experimental animal model of acoustic trauma were presented. In forty 3 months old guinea pigs the hearing threshold was ...
Wegman D H - - 1992
This report explores the importance of characterizing short-term (peak) exposures for successful epidemiologic study of acute reversible effects. By selecting upper respiratory tract irritation, which is time-limited, reversible, and not critically affected by host factor sensitivities, the illustrated approach (directed at an acute respiratory irritant) provides insights on issues important ...
Gerbaldo H - - 1992
Spontaneous light exposure patterns were studied in 10 chronic schizophrenic patients. Half of our schizophrenic patients exposed themselves to bright light exceeding ordinary indoor illumination. There was a significant positive correlation between the percentage of exposure to bright light and the Brief Psychiatric Rating Scale subscore anergia and a significant ...
Watanabe T - - 1992
The shortest stimulus exposure time for which transparency can be seen was examined. In the first experiment, overlapping digits were presented for 120 ms and the luminance in the overlapping regions was varied. Subjects reported, in separate blocks of trials, either the apparent transparency of the digits or the identity ...
Takeyama M - - 1992
To investigate whether the crossed olivo-cochlear bundle (COCB) functions in a protective manner, albino guinea pigs were exposed to sounds of varying intensity (110-130 dB SPL, 3-30 min) with or without electric stimulation of COCB, and the threshold shifts of the compound action potential (CAP) were examined. A statistically significant ...
Sthel M S - - 1991
The index-modulation evolution of a positive photoresist material was measured during the holographic exposure of sinusoidal patterns. The exposures were performed in a stabilized holographic setup that permits easy changes in the period. The results show the lowering of the recorded index modulation when the period decreases.
Kryter K D - - 1991
Hearing losses estimated for exposure to industrial and gun noise and for "typical" nosocusis are applied to the distributions of the hearing levels of adult males and females of the general population of an industrialized society unscreened for exposure to noise or ear disease. Noise exposure and demographic data applicable ...
Subramaniam M - - 1991
The effect of interrupted exposure on the development of progressive resistance to hearing loss from exposure to high frequency noise was studied using monaural chinchillas. The animals were exposed to an octave band noise centered at 4 kHz at 85 dB SPL for 6 h a day for ten consecutive ...
Hatch M - - 1991
An investigation into the effect of Carbogen (95% O2/5% CO2), 5% CO2/air, and 100% oxygen on cochlear threshold shifts caused by noise was undertaken. Five groups of eight pigmented guinea pigs were exposed to 105 dB broad band noise for 6 h per day for five consecutive days with each ...
Dunn D E - - 1991
The relative hazard posed to the peripheral auditory system by impact/impulse and continuous noise of the same power spectrum was determined. Impact noise was generated by striking a nail with a hammer and was digitally recorded. The acoustical power spectrum of the impact was determined and pink noise was filtered ...
Barrenäs M L - - 1991
In order to investigate the function of the inner ear melanin, noise-induced temporary hearing loss (temporary threshold shift, TTS) was studied in humans with either blue or brown iris colour. Sixty-eight normally hearing teenage boys participated in this study. Hearing thresholds before and after exposure were established with a computerized ...
Campo P - - 1991
The role of 'conditioning' exposures as moderators of hearing loss produced by exposure to a higher level noise was explored using chinchillas. Monaural chinchillas were exposed to an octave band of noise centered at 0.5 kHz at 95 dB for six hours/day for ten days. The subjects were allowed to ...
Gao W Y - - 1991
The recovery pattern of threshold shift (TS) and 'dynamic' changes in the stereocilia after exposure to high-level impulse noise in guinea pigs were investigated. 33 albino guinea pigs were exposed to 10 impulse noises at the rate of 1/min. The noise had peak level of 166 dB SPL and a ...
Robinson D W - - 1991
Audiometric repeatability is examined for a population of 356 male and female industrial employees (712 ears), sub-divided according to the amount of previous noise exposure. Re-tests were carried out after an interval averaging 13 months. After a similar interval, 150 of the subjects gave a third audiogram. Fixed-frequency self-recording audiometry ...
Ward W D - - 1991
Exposure of chinchillas to noise that is continuous results in auditory damage that is a function of the total energy of the exposure, provided that a critical exposure is not exceeded. Breaking a continuous exposure into 45 exposure periods given once a day Monday through Friday for 9 weeks (an ...
Clark W W - - 1991
It is well known that excessive exposure to noise results in temporary and/or permanent changes in hearing sensitivity in both human and animal subjects. The purpose of this review is to describe the major findings from laboratory studies of experimentally induced hearing losses, both temporary and permanent, resulting from exposure ...
Melnick W - - 1991
Information regarding the relation of human temporary threshold shift (TTS) to properties of steady-state and intermittent noise published since the 1966 appearance of the CHABA damage risk contours is reviewed. The review focuses on results from four investigative areas relevant to potential revision of the CHABA contours including effects of ...
Franklin D J - - 1991
Hearing sensitivity and the generation of acoustic-distortion products at 2f1-f2 were examined systematically in behaviorally trained rabbits, before, during, and following regular exposure to a 95-dB SPL octave band of noise, centered at 1 kHz. During the exposure period, the octave-band noise was interrupted once every 24 h in order ...
Stiller H - - 1991
The spectral radiance and irradiance of several common ophthalmic instruments were measured. The respective spectral retinal irradiance a patient might receive was calculated. To evaluate the potential light hazard to the patient's retina, we calculated the temperature rise resulting from light absorption at the fundus, compared retinal irradiance with threshold ...
Osguthorpe J D - - 1991
Chronic exposure to high-intensity noise can produce permanent hearing loss, the amount of which depends on noise intensity, temporal and spectral characteristics, and the length of exposure. OSHA regulates workplace noise exposure in accordance with the Hearing Conservation Amendment of 1983. When noise levels equal or exceed an 85 dBA ...
Rodriguez G P - - 1991
Noise-induced hearing loss following a broadband noise exposure has been characterized by a notch in the audiogram in the 3.0 to 6.0 kHz range. It has been postulated that loss of sensitivity in this frequency range is related to the primary resonant frequency of the external auditory meatus. In order ...
Westheimer G - - 1991
A briefly flashed pattern never appears quite sharp, and visual acuity is reduced with short exposures. These observations led to an examination of the effect of exposure duration on sharpness discrimination. A foveally seen edge appears just-discriminably blurred when its edge light distribution is changed from being sharp to conforming ...
Subramaniam M - - 1991
The effect of exposure level on the development of progressive resistance to temporary threshold shift caused by exposures to an octave band of noise centered at 0.5 kHz was explored using chinchillas. The animals were exposed to either 85, 95 or 100 dB SPL for six hours a day for ...
Henderson D - - 1991
The applicability of the equal energy hypothesis (EEH) to impact noise exposures was studied using chinchillas. Hearing thresholds were estimated by recording the evoked potentials from a chronic electrode implanted in the inferior colliculus. The animals were exposed to broadband impacts of 200-ms duration. The study was carried out in ...
Hu S Q - - 1991
The purpose of this study was to investigate the effects of two different pre-exposure procedures on adaptation to motion sickness in a rotating circular vection drum. The 45 subjects were randomly divided into three groups. The control group only had a standard 16-min exposure to the drum rotating at 60 ...
Ulfvarson U - - 1991
To assess the protective effect of exhausts pipe filters or respirators on pulmonary function, 15 workers in a tunnel construction site, truck and loading machine drivers, rock workers, and others were studied. The total and respirable dust, combustible matter in respirable dust, carbon monoxide, nitrogen monoxide and nitrogen dioxide were ...
Pirilä T - - 1991
Most epidemiological surveys concerning populations exposed to occupational noise or random populations have shown that the left ear is slightly but significantly poorer than the right ear, especially at frequencies most susceptible to noise damage. To experimentally study the possible left-right asymmetry in response to noise exposure, 28 non-shooting healthy ...
Fujita T - - 1991
The electrophysiological study of cochlear microphonics (CM), whole nerve action potential (AP) and endocochlear potential (EP) were examined. (1) With the extension of the exposure time of 500 Hz tone, a decrease of CM maximum output voltage in test frequency from 2 to 6 kHz was observed. (2) N1 potential ...
Okada H - - 1991
Morphological changes of the spiral vessels of guinea pig after rock music exposure (110-120 dB SPL, 1-3 h) were investigated. Characteristic of rock music is an almost incessant sound production with narrow dynamic range, and high energy in the low tone area. Morphometrical study showed that the lumina of the ...
Podoshin L - - 1991
The efficiency of Brainstem Auditory Evoked Potentials (BAEP) as an indicator of susceptibility to hazardous noise was investigated. In earlier studies, subjects were exposed to very intense occupational noise and temporary threshold shift (TTS) was produced by high intensity noise of 115 dB. Correlations between experimental TTS and the BAEP ...
Pirilä T - - 1991
The repeatedly noted average inferiority of the left ear (or superiority of the right ear) in epidemiological surveys at frequencies most susceptible to noise damage has not been experimentally confirmed. Twenty-eight non-shooting young adults were exposed binaurally to broad-band noise for a maximum of 8 h in strictly symmetrical laboratory ...
Dancer A - - 1991
Most of the available information on the effects of impulse noise on hearing is derived from temporary threshold shift (TTS2) measurements performed 2 min after a single exposure to small-weapon noises. TTS is known to recover as a linear function of the logarithm of time when it is induced by ...
Kateman E - - 1990
An influenza-like illness appeared recently among workers in a plant processing synthetic yarn. A humidifier, a cold-water spraying system, was the suspected cause. Lung function changes over the day and week and changes in blood leucocytes were studied among the workers from the suspected department and two reference populations. Exposure ...
Dobie T G - - 1990
It is well known that continued exposure to motion environments leads to adaptation, but it is not clear whether such changes are specific to the particular type of motion experienced. The present investigation sought to evaluate the extent of transfer between real motion and visually-induced apparent motion. In addition, the ...
Horner K C - - 1990
We have shown that experimentally-induced hydrops in the guinea pig systematically provokes an early low frequency (6.4 kHz and below) fluctuant hearing loss. The present study was aimed at investigating one aspect of the functioning of that part of the audiogram with normal CAP thresholds (mid and high frequencies) in ...
Fechter L D - - 1990
Trimethyltin chloride (TMT) produces an auditory impairment in the rat due, presumably, to cochlear injury. The loss is unusual in that it persists for several weeks, but ultimately resolves at least at low to middle frequencies. Recovery of high frequency auditory loss is less predictable. Given this pattern of injury ...
Brayman A A - - 1990
Plant root model cell systems have provided insight into the biophysical mechanism by which extremely low frequency electric fields (EF; f less than or equal to 100 Hz) affect nonexcitable eukaryotic cells. The evidence indicates that the plasma membrane is the site of interaction with applied extremely low frequency EF, ...
Emmerich E - - 1990
Impulse noise effects were tested in chronic experiments on 8 awake rabbits. Alterations of cochlear potentials and evoked responses from the inferior collinulus and the medial geniculate body were studied. The rabbits were subsequently exposed to 10 noise impulses of 144 dB SPL, then (after recovery) to 10 impulses of ...
Grenner J - - 1990
Thirty-three groups of guinea pigs, consisting of five animals in each group, were exposed to a simulated impact noise with peak levels ranging between 119.5 and 134.5 dB SPL. By varying the repetition rate, different equivalent levels could be set at each peak level. The equivalent levels ranged from 96 ...
Attias J - - 1990
Rats were exposed for 2 h either to 115 dB SPL noise, to 5% oxygen in nitrogen (hypoxia) or to both hypoxia and noise. Auditory nerve-brainstem evoked responses (ABR) to 80 dB HL clicks and threshold were recorded prior to exposure, immediately (5-10 min) after the exposure, 2 h after ...
Burbacher T M - - 1990
A qualitative and quantitative comparison of the neuropathological and neurobehavioral effects of early methylmercury (MeHg) exposure is presented. The focus of the qualitative comparison is the examination of how specific end-points (and categories of behavioral functions) compare across species. The focus of the quantitative comparison is the investigation of the ...
Wang J A - - 1990
Endocochlear potentials (EPs) were investigated in healthy guinea pigs and in those exposed to white noise of 125 dB SPL for 20-80 min. EPs were measured during and after temporary anoxia (3.5 min, denoted as reversible anoxia) and then during continuous anoxia to evaluate noise-induced changes in EP properties. Succino-dehydrogenase ...
Borsje R A - - 1990
Fluorophotometry was performed in 14 rabbits after exposure of one eye to white light with an energy insufficient to cause visible phototoxic retinal damage as determined by ophthalmoscopy and fundus photography. Fluorescence measurements in the vitreous were performed before and 1 hr after i.v. injection of fluorescein. Ratios between the ...
Johnson A C - - 1990
Rats were exposed to noise (100 dB Leq, 10 h/d, 7 d/w, 4 w), or to toluene (1,000 ppm, 16 h/d, 7 d/w, 2 w), or to noise followed by toluene. Auditory sensitivity was tested before exposure, and 1 to 4 weeks after exposure, by brainstem audiometry using a 1/3-octave ...
Harazin B - - 1990
The aim of this study was to determine the relationship between intensity, noise duration and non-auditory effect represented by changes both in visual acuity and the near point of accommodation. Changes in vision efficiency determined by a black and white chess board were monitored during and after 1 h exposure ...
Barrenäs M L - - 1990
In order to investigate the function of the inner ear melanin, the relationship between skin pigmentation and noise-induced temporary hearing loss (TTS) was studied. Forty-four normal-hearing Caucasian subjects were divided into three groups according to their sun sensitivity. Hearing thresholds before and after exposure were ascertained with a computerized sweep ...
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