New ISO Standards for Hearing Protectors (A)
Total Page:16
File Type:pdf, Size:1020Kb
Downloaded from orbit.dtu.dk on: Sep 25, 2021 New ISO standards for hearing protectors (A) Poulsen, Torben Published in: Acoustical Society of America. Journal Publication date: 2000 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Poulsen, T. (2000). New ISO standards for hearing protectors (A). Acoustical Society of America. Journal, 108(5), 2619-2619. General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. THURSDAY MORNING, 7 DECEMBER 2000 CATAMARAN ROOM, 8:25 TO 11:30 A.M. Session 4aAA Architectural Acoustics: Theme Park Acoustics David E. Marsh, Chair Pelton Marsh Kinsella, 1420 West Mockingbird Lane, #400, Dallas, Texas 75247-4932 Chair’s Introduction—8:25 Invited Papers 8:30 4aAA1. Challenges and more in the acoustic design of an attraction. Neil A. Shaw and Ray Van den Broeck ͑Menlo Sci. Acoust., Inc., P.O. Box 1610, Topanga, CA 90290-1610͒ Building a theme park from scratch involves not only providing a ‘‘theme’’ for the attractions contained therein, but also integrating the acoustic control and enhancement measures so that they work with, and not against, the goal of the attraction, which is the suspension of disbelief, at least for the age group to which the attraction is designed. The challenges encountered by the authors, the analysis of the same, as well as the proposed solutions, in the acoustic design for an enclosed attraction that includes hands-on interactive activities, live performances, and a roller coaster will be reviewed. Field work to determine potential mitigation paths will also be discussed. 9:00 4aAA2. Creativity in theme park acoustics. Marshall Long ͑Marshall Long Acoustics, 13636 Riverside Dr., Sherman Oaks, CA 91423, m_long@pacificnet.net͒ Theme parks are places where the entire environment is a theater in which the guests are active participants. As such it emphasizes creativity of concept and design, including acoustical design. Creative solutions have been found for acoustical problems including innovative uses of materials, mechanical and sound systems. A number of examples are presented from the author’s 20-year experi- ence with theme park acoustics illustrating examples of creative use of scientific principles. 9:30 4aAA3. Knott’s Camp Snoopy at the Mall of America: A theme park under glass, revisited. Steven J. Thorburn ͑2867 Grove Way, Castro Valley, CA 94546, [email protected]͒ Over ten years ago, the design of a special theme park was born. The plans for Knott’s Camp Snoopy at the Mall of America in Minneapolis, Minnesota would eventually grow into a popular tourist destination, but there were initial concerns about acoustics. The owners were familiar with the high noise levels of other indoor amusement parks and wanted to avoid that same situation. Having just completed the West Edmonton Mall, where many complaints were received about noise levels and guest visits were very short, it was very important to the owners that the design would prevent problems associated with noise. To do this, an acoustical consulting engineering firm was brought in. In this paper, the original acoustical design goals and solutions will be reviewed and compared against the final constructed project and its success over the first decade. 10:00 4aAA4. Community noise from theme parks. Ted N. Carnes ͑Pelton Marsh Kinsella, 1420 W. Mockingbird Ln., Ste. 400, Dallas, TX 75247͒ Theme and amusement parks are made to generate fun and excitement. As part of the guest experience a great amount of sound energy is often generated and it may be perceived as noise in the surrounding community. Defining outdoor noise criteria for the parks is often done for you by the local municipality zoning and building officials. Thus, one can use sound-modeling techniques to determine potential problems before the parks are built or expanded. While noise control of sound levels at the source is always desirable, there are many sources that defy their use. Thus, control of sound levels along the sound path is all that is often available. All of these concerns about theme parks will be addressed along with some suggestions on how to minimize community noise impacts. Some actual project examples will be discussed with the architectural acoustics aspects emphasized. 10:30 4aAA5. The impact of propagation anomalies on noise emissions from entertainment facilities. Robert Bronsdon ͑Walt Disney Imagineering, 1401 Flower St., Glendale, CA 91221͒ Most measurements made on environmental noise sources are done whenever it is convenient without any real consideration to the effects of environmental factors such as wind and temperature gradients. Predictions are typically done assuming that the atmospheric conditions are stable and benign. When the predictions and test results are compared and do not match, a generalization is given: ‘‘It 2580 J. Acoust. Soc. Am., Vol. 108, No. 5, Pt. 2, November 2000 Joint 140th Meeting ASA/NOISE-CON 2000 2580 Downloaded 28 Jun 2010 to 192.38.67.112. Redistribution subject to ASA license or copyright; see http://asadl.org/journals/doc/ASALIB-home/info/terms.jsp must have been caused by some type of atmospheric condition.’’ A computational Gaussian beam program that accounts for the effects of wind and temperature inversions was presented at Inter-noise 98 in New Zealand and is now currently a part of the SoundPLAN program for evaluating environmental noise. That program is designed primarily to deal with temperature inversions and wind that is blowing from the source to the receiver, but it does provide insight into upwind propagation. This paper explains how upwind propagation of sound in temperature inversion conditions can impact noise receivers in urban settings. 11:00 4aAA6. Noise abatement strategies and modeling approaches for outdoor attractions at theme parks. Christopher W. Menge ͑Harris Miller Miller & Hanson, Inc., 15 New England Executive Park, Burlington, MA 01803, [email protected]͒ Recent experience in noise abatement approaches and results for a new theme park are presented. Significant contributions from different source components on roller coasters lead to different abatement strategies taken for each. Measured source data will be presented. The relative performance of abatement applied separately to the source and sound path will be discussed, as well as the effects of source directivity. Source and propagation modeling approaches are presented, including how a customized version of a recently developed national noise model for highway traffic was applied for roller coasters and other sources. THURSDAY MORNING, 7 DECEMBER 2000 SCHOONER/SLOOP ROOMS, 7:25 A.M. TO 12:05 P.M. Session 4aAB Animal Bioacoustics: Instrumentation for Animal Bioacoustics Monitoring and Measurement William C. Burgess, Chair Greeneridge Sciences, 1411 Firestone Road, Goleta, California 93117 Chair’s Introduction—7:25 Invited Papers 7:30 4aAB1. Reflector microphones for field recording of natural sounds. George W. Swenson, Jr. ͑Dept. of Elec. and Computer Eng., Univ. of Illinois at Urbana-Champaign, 1308 W. Main St., Urbana, IL 61801, [email protected]͒ A directional microphone system for field recording of sounds in the air, for example, bird song or other animal activity, usually involves either a parabolic reflector to focus the sound waves on the microphone ͑transducer͒ element, or a linear array of transducers so phased as to respond preferentially to sounds from one directional sector. The latter system ͑the so-called ‘‘shotgun’’ microphone͒ can be analyzed in a fairly straightforward manner. The reflector system, however, involving as it does a structure comparable to a wavelength in linear dimension, is not susceptible to the conventional approximate methods of computation. Recently developed computational techniques now permit exact calculation of the directional responses of small reflectors. One result is a proposal for a very economical and effective system involving a plane reflector. No directional microphone can, in practice, reproduce sounds with fidelity to the sounds as emitted by the source. 7:50 4aAB2. Portable instrumentation for the recording, analysis, and playback of infrasonic animal vocalizations. Elizabeth von Muggenthaler ͑Fauna Commun. Res. Inst., P.O. Box 1126, Hillsborough, NC 27278͒ Several bioacoustic experiments required an affordable system capable of field recording, real-time analysis, signal editing, and real-time playback of infrasonic animal vocalizations. The synthesis of several types of recording devices and signal processing software has resulted in the capacity to record infrasound and perform analysis even during rain, heat, and high humidity. Small portable microphones and recorders can record in the field from 3 Hz to 22 kHz. On-site analysis including real-time FFT, color spectrographic function, filtering, cross-correlation, and other functions can be facilitated with the use of any portable computer with 92 Mbytes RAM. Signal editing, including frequency, amplitude, and cut/paste can be accomplished with readily available music signal processing software. Real-time field playback from 10 Hz to 45 kHz can be acheived by using portable car audio speakers. This 4a THU. AM system was used for the real-time analysis of elephant vocalizations, which were edited and played back immediately during recording sessions. It has also been used in field research involving tiger, binturong, rhinoceros, and giraffe. Tigers and elephants appear to respond behaviorally to real-time playback of original and edited vocalizations.