PubMed · 7094082
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
J Kiml. 1982. [Hearing protective devices].. https://pubmed.ncbi.nlm.nih.gov/7094082/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Occupational noise-induced hearing loss (NIHL) is an important yet often overlooked illness that can affect an individual's safety and performance at work. This article describes a state-based surveillance system for occupational NIHL. The Michigan surveillance system enables us to describe the magnitude of occupational NIHL among Michigan workers and direct public health interventions in the form of enforcement workplace inspections. The data presented are based on interviews of individuals with occupational NIHL reported to the Michigan Department of Consumer and Industry Services (MDCIS) by Michigan's audiologists and otolaryngologists from 1992-1997. From 1992-1997, 1378 individuals with occupational NIHL were reported to the MDCIS and interviewed about their exposures to noise at work. Over 70% of the workplace noise exposure were in manufacturing. At the most recent company where these individuals were exposed to noise, approximately 46% were not provided regular hearing testing. Regular hearing testing was more likely to occur in the larger companies and in industries covered by regulations requiring such testing to be performed. There were improvements over time in the percentages of companies providing regular hearing testing and hearing protection. Construction workers are employees among a group of industries that are not adequately protected from excessive noise exposures by occupational regulations. Regular hearing testing was not provided for over 90% of construction jobs, although hearing protection such as earplugs or earmuffs was provided for approximately half of these jobs. Forty-three state enforcement inspections were conducted at the companies reported by the patients interviewed, because these companies were reported to provide no regular hearing testing or no hearing protection despite exposures to excessive levels of noise. During the 43 inspections, 23 companies had noise levels above dBA, and 17 of those had either no hearing conservation program (HCP) or had one that was cited as being incomplete. The inspections potentially protected 758 similarly exposed workers in the companies with the high noise levels that lacked an HCP or that had a deficient HCP. The number of patients with occupational NIHL is likely a gross underestimate of the true magnitude of the disease. However, the surveillance system has identified workplaces with hazardous levels of noise and no HCP, thereby protecting similarly exposed coworkers of the index patients from further exposures to noise and hearing loss.
This paper is concerned with the analysis and design of a feedback control active eardefender. By using classical control theory, the authors investigated the system stability and robustness of stability, the noise reduction level and its parameter sensitivity, and the working frequency range of the active eardefender. A general method for designing a stable feedback control eardefender is developed. In this theory, a special type of second-order compensator is used to improve the robustness of stability, the noise reduction level and its robustness, and the working area of the active eardefender, particularly at the low-frequency range of interest.
Although industrial and recreational noise have been recognized as potential causes of noise-induced hearing loss for quite some time, it is only recently that the sound levels within a symphony orchestra have been implicated as possible sources of harmful noise levels. Many studies have concluded that not only are dangerous levels of noise present within the symphony orchestra, but there is evidence of noise-induced hearing loss among symphony orchestra musicians. Although hearing protection designed for industrial use may not be appropriate for the special listening needs of professional musicians, recent advances in hearing protection design have made hearing protection practical for this population. Suggestions are made for monitoring and protecting the professional ear.