Traditional Rating of Noise Versus Physiological Costs of Sound Exposures to the Hearing (Biomedical and Health Research)

In occupational safety and health acts, ordinances, regulations, directives, standards and guidelines, A-weighted sound exposures, varying in level and duration, are traditionally converted to an 8-hour-average sound level by applying the 3-dB exchange rate. Under the prerequisite that the energy equivalent rating level does not exceed 85 dB(A)/8 h, even impulse noise exposures of up to 140 dB are declared harmless. Indeed, the mutual settlement of level and duration based on the concept of energy equivalence is correct as far as sound energy or physical dose is concerned. However, between this principle and work physiological and work psychological, i.e. ergonomics paradigms, some decisive discrepancies do exist, and the dose maxim cannot be accepted from an ergonomics point of view. People react to exposures according to human characteristics rather than 'function' according to the laws of physics as they apply to inert matter. This has been demonstrated by a series of new experimental approaches, in which temporary threshold shifts and their restitution associated with various energy equivalent noise exposures have been measured. Also the impact of various types of loud music has been investigated. In addition to the conventionally determined maximum threshold shift, TTS2, and the time it takes to reach the resting hearing level again, the area under the restitution curve, i.e. the integrated restitution temporary threshold shifts, indicate the total physiological costs the hearing has to pay for a preceding sound exposure. Quite different statistically significant physiological responses to equally rated and legally tolerated sound exposures (94 dB(A)/1 h / 85 dB(A)/8 h) have repeatedly been measured. These refute the concept of energy-equivalence along virtually all dimensions, for example, substantially underestimating the risk of impulse noise, legalizing the 'filling' of resting periods with noise, ignoring the fact that short-term, high continuous noise is even quite favourable for the hearing, or prognosticating drastic losses in attenuation after short time periods of not wearing hearing protective devices, making them sound worse than they are. This book is an attempt to increase the transparency in existing evaluation methods and - in the interest of pertinent disclosure of risks associated with common procedures - to work towards the elimination of unacceptable simplifications and dangerously erroneous assessments.IOS Press is an international science, technical and medical publisher of high-quality books for academics, scientists, and professionals in all fields. Some of the areas we publish in: -Biomedicine -Oncology -Artificial intelligence -Databases and information systems -Maritime engineering -Nanotechnology -Geoengineering -All aspects of physics -E-governance -E-commerce -The knowledge economy -Urban studies -Arms control -Understanding and responding to terrorism -Medical informatics -Computer Sciences Title page 1 Preface 5 Contents 9 Problems of Measurement, Evaluation, and Rating of Environmental Exposures in Occupational Health and Safety Associated with the Dose Maxim and Energy Equivalence Principle 11 Impulse Noise Exposures, Present in Civil and Military Sectors 35 Noise Immissions from Working with Bolt Setting Tools in the Construction Sector 53 Methods for Quantifying Hearing Threshold Shifts of Sound Exposures and for Depicting the Parameters TTS2, t(0 dB), and IRTTS Indicating the Physiological Costs to the Hearing 63 Hearing Threshold Shifts and Restitution Course After Impulse and Continuous Noise at the Frequency of the Maximum Threshold Shift and the Adjacent Lower and Upper Frequencies 77 Hearing Threshold Shifts and Their Restitution as Physiological Responses to Legally Tolerable Continuous and Impulse Noise Exposures with a Rating Level of 85 dB(A) 91 Physiological Costs of Energy Equivalent Exposures to Continuous and Additional Energetically Negligible Noise 103 Influence of the Number of Impulses and the Impulse Duration on Hearing Threshold Shifts 115 Investigations into the Efficiency of the Stapedius Reflex with Impulse Noise Series 125 Physiological Costs of the Hearing After Exposures to White Noise, Industrial Noise, Heavy Metal, and Classical Music of 94 dB(A) for 1 Hour 137 Temporary Hearing Threshold Shifts and Restitution Associated with Exposures to Industrial Noise and Classical Music of 94 dB(A) for 1 Hour and 91 dB(A) for 2 Hours 147 Comparative Investigations into the Physiological Responses to Heavy Metal, Techno, and Classical Music 159 Effects of Noise Exposures During Physical Rest, Additional Physical Exercise and Combined Exposures to Alcohol and Cigarette Smoke on Hearing Threshold Shifts and Their Restitution 173 Quantification of the Insertion Loss of Personal Hearing Protection Devices by Means of a Subjective Method and an Artificial Head Measuring System 191 Substantial Protection Loss Associated with a Minimally Reduced Wearing Time of Hearing Protectors - Fiction or Reality? 201 Influence of Reduced Wearing Time on the Attenuation of Earplugs - Prognosis by the 3-dB Exchange Rate Versus Audiometric Measurements 213 Dubious Risk Prevention via Traditional Rating of Whole-Body Vibrations, UV Radiation, and Carbon Monoxide 221 Author Index 237

in Occupational Safety And Health Acts, Ordinances, Regulations, Directives, Standards And Guidelines, A-weighted Sound Exposures, Varying In Level And Duration, Are Traditionally Converted To An 8-hour-average Sound Level By Applying The 3-db Exchange Rate. Under The Prerequisite That The Energy Equivalent Rating Level Does Not Exceed 85 Db(a)/8 H, Even Impulse Noise Exposures Of Up To 140 Db Are Declared Harmless. Indeed, The Mutual Settlement Of Level And Duration Based On The Concept Of Energy Equivalence Is Correct As Far As Sound Energy Or Physical Dose Is Concerned. However, Between This Principle And Work Physiological And Work Psychological, I.e. Ergonomics Paradigms, Some Decisive Discrepancies Do Exist. People React To Exposures According To Human Characteristics Rather Than Function According To The Laws Of Physics As They Apply To Inert Matter. This Has Been Demonstrated By A Series Of New Experimental Approaches, In Which Temporary Threshold Shifts And Their Restitution Associated With Various Energy Equivalent Noise Exposures Have Been Measured. Also The Impact Of Various Types Of Loud Music Has Been Investigated. In Addition To The Conventionally Determined Maximum Threshold Shift, Tts2, And The Time It Takes To Reach The Resting Hearing Level Again, The Area Under The Restitution Curve, Indicate The Total Physiological Costs The Hearing Has To Pay For A Preceding Sound Exposure. This Book Is An Attempt To Increase The Transparency In Existing Evaluation Methods And In The Interest Of Pertinent Disclosure Of Risks Associated With Common Procedures To Work Towards The Elimination Of Unacceptable Simplifications And Dangerously Erroneous Assessments.