Prediction of NIPTS Due to Continuous Noise Exposure

1973 ◽  
Author(s):  
Daniel L. Johnson
Keyword(s):  
Noise Exposure ◽  
Continuous Noise

Temporary Threshold Shift following 24-Hour Noise Exposure

1977 ◽  
Vol 86 (6) ◽  
pp. 821-826 ◽  
Author(s):  
William Melnick
Keyword(s):  
Noise Level ◽  
Noise Exposure ◽  
Sound Field ◽  
Threshold Shift ◽  
Exposure Level ◽  
Temporary Threshold Shift ◽  
Octave Band ◽  
Straight Line ◽  
Hearing Thresholds ◽  
Continuous Noise

Nine men were exposed to 24 hours of continuous noise in a sound field. The noise was an octave band centered at 4 kHz at levels 80 and 85 dB. Hearing thresholds were measured monaurally at 11 test frequencies ranging from 250 to 10000 Hz before, during, and after exposure. Temporary threshold shift (TTS) reached maximum levels at 8 to 12 hours of exposure. Maximum TTS occurred at 4 and 6 kHz. Mean asymptomtic threshold shifts (ATS) resulting from the 80 dB exposure level were 9.3 dB for 4 kHz and 7.2 dB for 6 kHz. For the 85 dB noise level, these threshold shifts were 17.8 dB and 14.6 dB respectively. The increase in ATS with increase of noise level for these two frequencies could be fitted with a straight line having a slope of 1.6.

Intermittent Exposure to Noise: Effects on Hearing

1983 ◽  
Vol 92 (6) ◽  
pp. 623-628 ◽  
Author(s):  
Joseph Sataloff ◽  
Robert T. Sataloff ◽  
Raymond A. Yerg ◽  
Hyman Menduke ◽  
Robert P. Gore
Keyword(s):  
Hearing Loss ◽  
Noise Exposure ◽  
Continuous Exposure ◽  
Hearing Results ◽  
Noise Effects ◽  
High Frequencies ◽  
Severe Loss ◽  
Intermittent Exposure ◽  
Intense Noise ◽  
Continuous Noise

Most studies of the effects of noise upon hearing have dealt with continuous noise exposure. Previous reports on intermittent exposure to noise concluded that it causes less damage to hearing than does continuous exposure to noise of the same intensity. In this investigation, 12,000 workers were screened to find 295 subjects who met the strict criteria of the study. Most of the subjects were exposed to jackhammer noise at peak levels of 118 dBA. Intermittent exposure to intense noise results in very severe loss in high frequencies but relatively little or no hearing loss in the lower frequencies even after many years of exposure. This differs substantially from the effects of continuous exposure to noise of the same intensity. It remains to be determined whether this pattern of hearing results from intermittent exposure to all sorts of noise or only from the kinds of sources investigated in this study.

Reduction in Impulse Noise-Induced Permanent Threshold Shift with Intracochlear Application of an NADPH Oxidase Inhibitor

2013 ◽  
Vol 24 (06) ◽  
pp. 461-473 ◽  
Author(s):  
Eric C. Bielefeld
Keyword(s):  
Reactive Oxygen Species ◽  
Nadph Oxidase ◽  
Impulse Noise ◽  
Noise Exposure ◽  
Oxidase Inhibitor ◽  
Threshold Shift ◽  
Distilled Water ◽  
Oxygen Species ◽  
Nadph Oxidase Inhibitor ◽  
Continuous Noise

Background: Toxic levels of reactive oxygen species are key contributors to the lesion of dead outer hair cells (OHCs) seen in the cochlea after noise exposure. The current study follows previous work in which paraquat was used to demonstrate that NADPH oxidase is active in the cochlea and can contribute to cochlear reactive oxygen species formation and hair cell loss. Purpose: The current study was undertaken to test whether pharmacological blockade of NADPH oxidase in the cochlea would lead to reduced noise-induced hearing loss and OHC death. Study Sample: A total of 18 chinchillas (36 ears) were assessed in the study. Intervention: AEBSF (4-[2-aminoethyl]benzenesulfonyl fluoride), an inhibitor of NADPH oxidase activation, was dissolved in distilled water and delivered into the cochlea via diffusion across the round window membrane. The contralateral ears received distilled water as a vehicle control. Following treatment, chinchillas were exposed to one of two noises: a 4 kHz octave band noise at 106 dB SPL for 6 hr or an impulse noise that consisted of 75 pairs of 155 dB pSPL impulses. Data Collection and Analysis: Pre– and post–noise exposure, thresholds of the auditory brainstem response at 2–8 kHz were measured. Postmortem OHC counts were conducted at the conclusion of the study. Two- and three-factor ANOVAs were used for statistical analysis of the OHC losses and ABR threshold shifts induced by the noise exposures. Results: Permanent threshold shift from the impulse noise was reduced in the ears treated with the NADPH oxidase inhibitor, but no differences were found in the groups exposed to the continuous noise. OHC losses were not statistically different between the treated and untreated ears for either noise exposure. Conclusions: The results suggest that NADPH oxidase-mediated superoxide has a role in cochlear damage from impulse noise, and pharmacologic inhibition of NADPH oxidase can reduce cochlear susceptibility to noise damage. The lack of protection from the longer-duration continuous noise can be attributed to a number of possibilities related to dose level and delivery schedule.

Hearing loss in the chinchilla from impact and continuous noise exposure

1991 ◽  
Vol 90 (4) ◽  
pp. 1979-1985 ◽  
Author(s):  
Derek E. Dunn ◽  
Rickie R. Davis ◽  
Carol J. Merry ◽  
John R. Franks
Keyword(s):  
Hearing Loss ◽  
Noise Exposure ◽  
Continuous Noise

scholarly journals Investigation continuous noise exposure and occupational performance of the workers in the pharmaceutical industry: A Case Study in an Ampoule and Vial Production Industry

2019 ◽  
Author(s):  
I Alimohammadi ◽  
F Ahmadi Kanrash ◽  
R Soltani Gerdefaramarzi ◽  
N Nouri
Keyword(s):  
Pharmaceutical Industry ◽  
Production Line ◽  
Inverse Relationship ◽  
Noise Exposure ◽  
P Value ◽  
Occupational Performance ◽  
Negative Effects ◽  
Cross Sectional ◽  
Continuous Noise ◽  
The Relationship

Introduction: Exposure to noise is considered as one of the most important health problems in various industries, especially pharmaceutical industry, which can ultimately lead to significant negative effects on labor force and occupational performance. The aim of this study was to investigate the relationship between continuous noise exposure and occupational performance of the workers in the pharmaceutical industry and ampoule production line in Iran. Method: This cross-sectional study was conducted through a descriptive-analytical method in 2015. The subjects were 100 workers exposed to noise in an ampoule and vial manufacturing factory in Iran. The sound measurement was carried out in accordance with ISO 9612: 2009. The Hersey and Goldsmith questionnaire (ACHIEVE model) was used to investigate the workers’ occupational performance, and the seven dimensions of the questionnaire as well as the final score of occupational performance was determined for each individual. Results: The results showed that there was a low inverse relationship between noise exposure and occupational performance of the total workers in all the halls which was statistically significant (P-value = 0/01, r2 = 0/256). It was also found that there was an inverse relationship between exposure to noise and the seven dimensions, but the relationship was statistically significant only for the dimensions of ability, clarity, and evaluation (P-value <0.05). Conclusion: The present study showed that the workers in the pharmaceutical industry and ampoule production line were often exposed to higher-than-permitted sound level, and such exposures had negative effects on their occupational performance.

Noise exposure criteria for continuous noise: A case for reducing the 8 hour open ear exposure level

2015 ◽  
Vol 138 (3) ◽  
pp. 1803-1804
Author(s):  
Hilary Gallagher ◽  
Richard L. McKinley ◽  
Melissa A. Theis ◽  
Elizabeth A. McKenna
Keyword(s):  
Noise Exposure ◽  
Exposure Level ◽  
Continuous Noise
Sign in / Sign up

Export Citation Format

Share Document