Download or read book The Role of Peak Pressure in Determining the Auditory Hazard of Impulse Noise written by James H. Patterson (Jr.) and published by . This book was released on 1986 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most current Damage Risk Criteria (DRC) for human exposure to impulse noise are written in terms of peak pressure as the primary index of the traumatic potential or hazard associated with exposure to an impulse noise. Since the peak pressure is only one of many parameters of an impulse, there is a question whether or not a DRC based on peak pressure can reflect accurately the hazard to hearing posed by impulse noise. The experiments described in this report were designed to determine whether peak pressure is an adequate quantifier for an impulse noise DRC. The general approach was to construct two types of impulse noise with the same Fourier pressure spectrum, but with different peak pressures. This makes it possible to compare the hearing loss and injury resulting from impulses which have the same total energy distributed the same way across frequency, but with different peak pressures. The threshold shift measured during the first few hours after exposure showed systematic variation with both peak pressure and energy level. The permanent threshold shift (20 to 30 days postexposure) and the loss of sensory cells showed strong dependence on energy level, with a less pronounced dependence on peak pressure. These results indicate that peak pressure is not a sufficient indicator of auditory hazard; however, energy alone is not a sufficient indicator either. Keywords: Exposure (Physiology), Impulse noise.
Download or read book Basic and Applied Aspects of Noise Induced Hearing Loss written by Richard J. Salvi and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 655 pages. Available in PDF, EPUB and Kindle. Book excerpt: In September 1985, NATO sponsored an Advanced Study WOl'kshop entitled, "Noise-Induced Hearing Loss: Basic and Applied Aspects." Tne meeting was held in a mountain retreat near Lucca, Italy and was attended by scientists, clinicians, and public officials from 12 countries. This was the third in a series of such conferences organized by the authors. The first two were supported by the United States National Institute of Occupational Safety and Health; their proceedings were published as "The Effects of Noise on Hearing" in 1976 and "New Perspectives on Noise-Induced Hearing Loss" in 1982. The Organizing Committee approached NATO because it was felt that the problem of noise was common to all industrialized countries and was an especially serious problem for the military. Thus, the NATO sponsorship and the Italian site of the meeting were part of the Organizing Committee's plan to obtain an international and thorough repr'esentation on the problem of noise-induced hearing loss. The NATO meeting and proceedings followed the format of the previous two symposia with an initial focus on the anatomical and physiological disturbances resulting from noise-induced hearing loss. This was followed by sections devoted to studies of a more applied nature involving general auditory performance in noise, issues associated with the establishment of noise-exposure criteria, nonauditory effects of noise, and the interaction of noise with other agents.
Download or read book Hazardous Exposure to Impulse Noise written by and published by . This book was released on 1992 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Limits for exposure to hazardous agents are set by defining some specific acceptable effect (the response) and then determining what exposure conditions (the dose) produce that effect. In 1968, the Committee on Hearing, Bioacoustics, and Biomechanics (CHABA) proposed a limit for exposure to impulse noise (gunfire) in which the response was a specific amount of temporary threshold shift (TTS) and dose was specified in terms of the peak pressure and two aspects of the duration of a particular impulse, with correction factors for number of impulses and for the angle of incidence on the ear. The proposal was basically an endorsement of one advanced by an Anglo-American team of investigators (Coles, Garinther, Hodge, and Rice, 1968) that was based on the very limited pool of information then available about the auditory hazard of gunfire. Coles, Garinther, and Hodge were members of the Working Group on Proposed Damage-Risk Criterion for Impulse Noise (Gunfire).
Download or read book Energy Research Abstracts written by and published by . This book was released on 1989 with total page 1398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shock Trial of the Winston S Churchill DDG 81 written by and published by . This book was released on 1999 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Impulse Noise and Hazard Analysis of Impulse Noise Induced Hearing Loss Using AHAAH Modeling written by Qing Wu and published by . This book was released on 2014 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Millions of people across the world are suffering from noise induced hearing loss (NIHL), especially under working conditions of either continuous Gaussian or non-Gaussian noise that might affect human's hearing function. Impulse noise is a typical non-Gaussian noise exposure in military and industry, and generates severe hearing loss problem. This study mainly focuses on characterization of impulse noise using digital signal analysis method and prediction of the auditory hazard of impulse noise induced hearing loss by the Auditory Hazard Assessment Algorithm for Humans (AHAAH) modeling. A digital noise exposure system has been developed to produce impulse noises with peak sound pressure level (SPL) up to 160 dB. The characterization of impulse noise generated by the system has been investigated and analyzed in both time and frequency domains. Furthermore, the effects of key parameters of impulse noise on auditory risk unit (ARU) are investigated using both simulated and experimental measured impulse noise signals in the AHAAH model. The results showed that the ARUs increased monotonically with the peak pressure (both P + and P- ) increasing. With increasing of the time duration, the ARUs increased first and then decreased, and the peak of ARUs appeared at about t = 0.2 ms (for both t+ and t- ). In addition, the auditory hazard of experimental measured impulse noises signals demonstrated a monotonically increasing relationship between ARUs and system voltages.
Download or read book Characterization of Impulse Noise and Hazard Analysis of Impulse Noise Induced Hearing Loss Using AHAAH Modeling written by Qing Wu (‡e author) and published by . This book was released on 2014 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: Millions of people across the world are suffering from noise induced hearing loss (NIHL), especially under working conditions of either continuous Gaussian or non-Gaussian noise that might affect human's hearing function. Impulse noise is a typical non-Gaussian noise exposure in military and industry, and generates severe hearing loss problem. This study mainly focuses on characterization of impulse noise using digital signal analysis method and prediction of the auditory hazard of impulse noise induced hearing loss by the Auditory Hazard Assessment Algorithm for Humans (AHAAH) modeling. A digital noise exposure system has been developed to produce impulse noises with peak sound pressure level (SPL) up to 160 dB. The characterization of impulse noise generated by the system has been investigated and analyzed in both time and frequency domains. Furthermore, the effects of key parameters of impulse noise on auditory risk unit (ARU) are investigated using both simulated and experimental measured impulse noise signals in the AHAAH model. The results showed that the ARUs increased monotonically with the peak pressure (both P + and P- ) increasing. With increasing of the time duration, the ARUs increased first and then decreased, and the peak of ARUs appeared at about t = 0.2 ms (for both t+ and t- ). In addition, the auditory hazard of experimental measured impulse noises signals demonstrated a monotonically increasing relationship between ARUs and system voltages.
Download or read book Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1989-03 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technology for a Quieter America written by National Academy of Engineering and published by National Academies Press. This book was released on 2010-10-30 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exposure to noise at home, at work, while traveling, and during leisure activities is a fact of life for all Americans. At times noise can be loud enough to damage hearing, and at lower levels it can disrupt normal living, affect sleep patterns, affect our ability to concentrate at work, interfere with outdoor recreational activities, and, in some cases, interfere with communications and even cause accidents. Clearly, exposure to excessive noise can affect our quality of life. As the population of the United States and, indeed, the world increases and developing countries become more industrialized, problems of noise are likely to become more pervasive and lower the quality of life for everyone. Efforts to manage noise exposures, to design quieter buildings, products, equipment, and transportation vehicles, and to provide a regulatory environment that facilitates adequate, cost-effective, sustainable noise controls require our immediate attention. Technology for a Quieter America looks at the most commonly identified sources of noise, how they are characterized, and efforts that have been made to reduce noise emissions and experiences. The book also reviews the standards and regulations that govern noise levels and the federal, state, and local agencies that regulate noise for the benefit, safety, and wellness of society at large. In addition, it presents the cost-benefit trade-offs between efforts to mitigate noise and the improvements they achieve, information sources available to the public on the dimensions of noise problems and their mitigation, and the need to educate professionals who can deal with these issues. Noise emissions are an issue in industry, in communities, in buildings, and during leisure activities. As such, Technology for a Quieter America will appeal to a wide range of stakeholders: the engineering community; the public; government at the federal, state, and local levels; private industry; labor unions; and nonprofit organizations. Implementation of the recommendations in Technology for a Quieter America will result in reduction of the noise levels to which Americans are exposed and will improve the ability of American industry to compete in world markets paying increasing attention to the noise emissions of products.
Download or read book The Journal of the Acoustical Society of America written by Acoustical Society of America and published by . This book was released on 2007 with total page 1552 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hazard from an Intense Midrange Impulse written by and published by . This book was released on 1989 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been hypothesized that the ear would become increasingly susceptible to impulses (gunfire) as the spectral peak of the impulse approached the frequency region where the ear was tuned best (about 4 kHz for the cat ear) (G.R. Price, J. Acoust. Soc. Am. Suppl. 1 62, S95 (1977)). This prediction was counter to the predictions of the world's damage-risk criteria for impulse noise. It has been supported by experiments using exposures to 100-Hz and 800- to 1000-Hz impulses; but no test had been run at the point of predicted maximum susceptibility. In the present experiment, three groups of cats were exposed to 50 impulses produced by a primer explosion (spectral peak at 4 kHz) at peak levels of 135, 140, or 145 dB. Auditory thresholds were electrophysiologically measured from the vertex to 2-, 4-, 8-, and 16-kHz tone pips and losses were determined 30 min after exposure and more than 2 months post-exposure. Losses were greatest at 4 kHz, began to develop at 134-dB peak pressure, and the immediate losses grew at a rate of about 7 dB for every dB increase in peak pressure. About half of the loss measured immediately became permanent. The energy required to begin producing a permanent threshold shift was only about 0. 07 J/m squared, far lower than that required with continuous noises at lower sound pressures. The data were interpreted as supporting the original hypothesis of greater susceptibility in the midrange.
Download or read book Noise and Military Service written by Institute of Medicine and published by National Academies Press. This book was released on 2006-01-20 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Institute of Medicine carried out a study mandated by Congress and sponsored by the Department of Veterans Affairs to provide an assessment of several issues related to noise-induced hearing loss and tinnitus associated with service in the Armed Forces since World War II. The resulting book, Noise and Military Service: Implications for Hearing Loss and Tinnitus, presents findings on the presence of hazardous noise in military settings, levels of noise exposure necessary to cause hearing loss or tinnitus, risk factors for noise-induced hearing loss and tinnitus, the timing of the effects of noise exposure on hearing, and the adequacy of military hearing conservation programs and audiometric testing. The book stresses the importance of conducting hearing tests (audiograms) at the beginning and end of military service for all military personnel and recommends several steps aimed at improving the military services' prevention of and surveillance for hearing loss and tinnitus. The book also identifies research needs, emphasizing topics specifically related to military service.
Download or read book Shock Testing the Seawolf Submarine written by and published by . This book was released on 1998 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acta oto laryngologica written by and published by . This book was released on 1993-07 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Information on Levels of Environmental Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety written by United States. Office of Noise Abatement and Control and published by . This book was released on 1974 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oversight Hearings on OSHA occupational Safety and Health for Federal Employees written by United States. Congress. House. Committee on Education and Labor. Subcommittee on Health and Safety and published by . This book was released on 1983 with total page 876 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oversight Hearings on OSHA occupational Safety and Health for Federal Employees Federal sector written by United States. Congress. House. Committee on Education and Labor. Subcommittee on Health and Safety and published by . This book was released on 1980 with total page 876 pages. Available in PDF, EPUB and Kindle. Book excerpt:
