Showing papers on "Noise pollution published in 1989"
01 Mar 1989
TL;DR: In this article, the authors measured tone audiograms and speech-reception thresholds in 200 individuals (400 ears) with noise-induced hearing loss and found that hearing loss in the regions above 3 kHz, from 1 to 3 kHz and below 1 kHz was related to speech reception in noise.
Abstract: Tone thresholds and speech-reception thresholds were measured in 200 individuals (400 ears) with noise-induced hearing loss. The speech-reception thresholds were measured in a quiet condition and in noise with a speech spectrum at levels of 35, 50, 65, and 80 dBA. The tone audiograms could be described by three principal components: hearing loss in the regions above 3 kHz, from 1 to 3 kHz and below 1 kHz; the speech thresholds could be described by two components: speech reception in quiet and speech reception in noise at 50-80 dBA. Hearing loss above 1 kHz was related to speech reception in noise; hearing loss at and below 1 kHz to speech reception in quiet. The correlation between the speech thresholds in quiet and in noise was only R = 0.45. An adequate predictor of the speech threshold in noise, the primary factor in the hearing handicap, was the pure-tone average at 2 and 4 kHz (PTA2,4, R = 0.72). The minimum value of the prediction error for any tone-audiometric predictor of this speech threshold was 1.2 dB (standard deviation). The prediction could not be improved by taking into account the critical ratio for low-frequency noise nor by its upward spread of masking. The prediction error is due to measurement error and to a factor common to both ears. The latter factor is ascribed to cognitive skill in speech reception. Hearing loss above 10 to 15 dB HL (hearing level) already shows an effect on the speech threshold in noise, a noticeable handicap is found at PTA2,4 = 30 dB HL.
257 citations
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01 Jul 1989TL;DR: In this paper, the comparative advantages of prospective SST engine noise-suppression systems, with a view to their effectiveness in meeting the federally-mandated community noise standards of FAR 36 Stage III, were evaluated.
Abstract: An evaluation is made of the comparative advantages of prospective SST engine noise-suppression systems, with a view to their effectiveness in meeting the federally-mandated community noise standards of FAR 36 Stage III. A noise-suppression system must be capable of removing at least 4 EPNdB of noise percent thrust loss at takeoff. While none of the suppressors presently discussed is capable of meeting this goal, the inverted velocity profile/annular convergent-divergent plug/acoustically-treated ejector suppressor combination of configurational elements appears to represent the most efficient noise-control apparatus. Noncircular cross-section nozzle geometries also furnish a general noise reduction advantage over circular ones.
66 citations
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TL;DR: In this paper, a double-wall vacuum jacket encompassing a compressor in the vacuum jacket so that the noise caused in a run-ign compressor will not be transmitted outwardly through a vacuum chamber formed in the double wall vacuum jacket for preventing noise pollution in an air conditioner.
Abstract: A noise-preventive apparatus for compressor used in an air conditioner includes a double-wall vacuum jacket encompassing a compressor in the vacuum jacket so that the noise caused in a runnign compressor will not be transmitted outwardly through a vacuum chamber formed in the double-wall vacuum jacket for preventing noise pollution in an air conditioner.
32 citations
01 Aug 1989
TL;DR: In this article, the relative magnitudes and effects on marine mammals of noise from oil and gas industry activities with noise from other sources in Alaska OCS and coastal waters were compared.
Abstract: The study compares the relative magnitudes and effects on marine mammals of noise from oil and gas industry activities with noise from other sources in Alaska OCS and coastal waters. The study procedure incorporates the receiver, source and path concepts generally used in acoustic analysis. The receiver characterization includes a review of marine mammal distribution in Alaska and a map of the distribution of each major species. Information on species sound production, hearing sensitivity (when known), and observed responses to noise sources is also included. The analysis of noise sources found in the Alaskan marine environment considers natural, industrial, transportation, and cultural sources. Acoustic transmission loss characteristics obtained from measurements and model predictions are used to estimate the effective ranges of the noise sources using available source level information. Information on species distribution was combined with information on source distribution, source level, and transmission loss to determine the most significant sources in terms of their acoustic range and the numbers of mammals potentially affected by developing a Standardized Noise Contribution Model species.
28 citations
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TL;DR: In this paper, the authors investigated whether there is any adaptation to this effect, carried out by repeating the “after” phase of two previous studies of decreases in noise exposure, and found that the effect of change is persistent over a period of at least two years, and a major part of it is visible over 7-9 years.
25 citations
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TL;DR: In this article, the authors discuss water pollution in parts of the Chao Phraya river, subsidence and flooding, and measures to resolve these problems and discuss air and noise pollution, environment in workplaces and the collection and disposal of solid wastes.
Abstract: Coming to terms with Bangkok's environmental problems concentrates on those associated with water: its supply and quality; the high levels of pollution in parts of the Chao Phraya river; subsidence and flooding; and measures to resolve these problems It also discusses air and noise pollution, the environment in workplaces and the collection and disposal of solid wastes
24 citations
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TL;DR: A significant correlation was found between sleep disturbance and traffic noise when the noise is expressed in EPNdB, and in the home experiments the subjects appeared to be approximately 10 dB less sensitive to noises than laboratory subjects for similar noise exposure.
Abstract: The disturbance of sleep by traffic noise is a major problem area in noise pollution. Extensive laboratory tests using multichannel electroencephalograms (EEG) have been carried out by many workers to determine the general response of people when exposed to noise during sleep. An experimental technique for obtaining results in people’s homes has been developed using a simplified one‐channel EEG. The responses of six people in the age range 19–24 were measured. A significant correlation was found between sleep disturbance and traffic noise when the noise is expressed in EPNdB. In the home experiments the subjects appeared to be approximately 10 dB less sensitive to noises than laboratory subjects for similar noise exposure. There also appeared to be some adaptation to the noise exposure; however, only one subject was tested for a period of 20 days and was insufficient to give definite results on adaptation.
22 citations
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TL;DR: In this paper, the authors proposed that each transportation system, highspeed rail HSR included, has its own noise spectra, characteristic air pollutant, which is a nemesis to modern society.
Abstract: Transportation noise and air pollution problems are a nemesis to our modern society. Each transportation system, highspeed rail HSR included, has its own noise spectra, characteristic air pollutant...
20 citations
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TL;DR: Ethics committees for clinical research: experience in the UK and improving the network of local ethical research committees and the establishment of a national ethical research committee.
Abstract: 1 National Childbirth Trust. Clinical trials and medical research-helping you decide. London: NCT, 1988. 2 Medical Research Council. Responsibility in investigations on human subjects. Report of the MRC for the year 1962-3. London: HMSO, 1964:21-5. (Cmnd 2382.) 3 Royal College of Physicians. Supervision of the ethics of clinical research investigations in institutions. London: HMSO, 1%7 (updated 1973). 4 Ministry of Health. Supervision of the ethics of clinical research. London: HMSO, 1968. (HM (68) 33.) 5 World Medical Association. Declaration of Helsinki: recommendations guiding physicians in biomedical research involving human subjects. Helsinki: WMA, 1964 (amended Tokyo 1975 and Venice 1983). 6 Department of Health and Social Security. Supervision of the ethics of clinical research investigations and fetal research. London: HMSO, 1975. (HSC (IS) 153.) 7 British Medical Association, Royal College of General Practitioners, and Association of British Pharmaceutical Industries. Code of practice for the clinical assessment of licensed medicinal products in general practice. BrMedJ 1983;286:1295-7. 8 Association of British Pharmaceutical Industries. Guidelines: clinical trialscompensation for medically induced injury. London: ABPI, 1983. 9 Department of Health and Social Security. Administration of radioactive substances to persons: London: HMSO, 1984. (HN (84) 5.) 10 Royal College of Physicians. Guidelines on the practice of ethics committees in medical research. London: RCP, 1984. 11 British Medical Association Central Ethical Committee. Improving the network of local ethical research committees and the establishment of a national ethical research committee. London: BMA, 1986. 12 Royal College of Physicians. Research on healthy volunteers. J R Coll Physicians Lond 1986;20:243-7. 13 Association of British Pharmaceutical Industries. Guidelines for medical experiments in non-patient human volunteers. London: ABPI, 1988. 14 Association of Independent Clinical Research Contractors. Guidelines for research ethics committees. Cardiff: AICRC, 1989. 15 King J. Informed consent. Institute ofMedical Ethics Bulletin 1986; suppl 3. 16 Diamond AL, Laurence DR. Compensation and drug trials. Br Med J 1983;287:675-7. 17 Lord Scarmen. Consent, communication and responsibility J R Soc Med 1986;79:697-700. 18 Thompson IE, French K, Melia KM, Boyd KM, Templeton AA, Potter B. Research ethical committees in Scotland. BrMedJ 1981;282:718-20. 19 Anonymous. Local ethics committees [Editoriali. BrMed, 1981;282:1010. 20 Wells FO, Griffin JP. Ethics committees for clinical research: experience in the UK. Drugs 1989;37:229-32. 21 Nicholson RH, ed. Medical research on children: ethics, law and practice. Oxford: Oxford Medical Publications, 1986.
15 citations
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TL;DR: The most noticeable sources of noise pollution in Karachi, are the autorickshaws, trail motor bikes and the fag horns of public transport.
Abstract: The menace of noise is a by-product of civilization and its hazards are well known. Noise levels were measured in Karachi, at different places and at different times of the night and day, using an Amplaid noise meter. The leg for Karachi came to 80 dB (A), the General Noise Index x (G.N.I.) to 460, and the noise pollution level (N.P.L.) to 99 dB (A). These values are significantly higher (P less than 0.01) than the available international data. The sources of noise production were indentified as, the road traffic, human activity, industrial and civil works, mechanical and engineering workshops. The most noticeable sources of noise pollution in Karachi, are the autorickshaws, trail motor bikes and the fag horns of public transport (JPMA 39-62, 1989).
9 citations
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01 Jul 1989TL;DR: In this article, a projection is made of the technology development requirements faced by aircraft designers contemplating the evolution of V-22-type tilt-rotor aircraft technology into a civilian tiltrotor commuter aircraft of the requisite scale and payload.
Abstract: A projection is made of the technology-development requirements faced by aircraft designers contemplating the evolution of V-22-type tilt-rotor aircraft technology into a civilian tilt-rotor commuter aircraft of the requisite scale and payload. These research challenges are noted to often involve the reduction of noise level to values tolerated by passengers within the cabin and communities in the vicinity of airports, especially during hover and in the course of transition from vertical to horizontal flight (and vice-versa). Noise-generation and noise-radiation characteristics research has been undertaken using the XV-15 tilt-rotor proof-of-concept aircraft.
01 Jan 1989
TL;DR: ORNAMENT evaluates a reference sound level and adjusts if by a series of adjustments accounting for the gradient of the roadway, the pavement surface, the distance between the road and the receiver, the topography and any shielding obstructing the sound path.
Abstract: Background and description of a procedure to predict road traffic noise based on road traffic parameters, receiver description and topographical features. The Ministry of the Environment requires the use of this method to assess the noise impact from existing roadways on planned residential land uses, to assess the noise impact of roadway projects, and to establish the ambient noise level criterion for approval of new noise sources and for complaint investigation. Based on a model developed by the U.S. Federal Highway Administration, ORNAMENT evaluates a reference sound level and adjusts if by a series of adjustments accounting for the gradient of the roadway, the pavement surface, the distance between the road and the receiver, the topography and any shielding obstructing the sound path. It is valid from 15 m to about 500 m, with decreasing accuracy after that distance. The method does not apply to traffic volumes less than 40 vehicles per hour and to speeds less than 50 km/h.
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01 Apr 1989TL;DR: In this paper, the annoyance of flyover noise from advanced turboprop aircraft having different propeller configurations with respect to other aircraft was compared to conventional turboprops and jet aircraft flyover noises.
Abstract: A laboratory experiment was conducted to compare the annoyance of flyover noise from advanced turboprop aircraft having different propeller configurations with the annoyance of conventional turboprop and jet aircraft flyover noise. It was found that advanced turboprops with single-rotating propellers were, on average, slightly less annoying than the other aircraft. Fundamental frequency and tone-to-broadband noise ratio affected annoyance response to advanced turboprops but the effects varied with propeller configuration and noise metric. The addition of duration corrections and corrections for tones above 500 Hz to the noise measurement procedures improved prediction ability.
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TL;DR: In this paper, a noise rights approach is suggested to address this problem, and applied to the Israeli case, based on the existing institutional structure there, and the applicability of the noise-rights approach to other contexts and to air and rail transportation is also discussed.
18 Dec 1989
TL;DR: In this article, the authors apply a NSBIT-developed probabilistic model to a body of social survey findings described by Fidell, Barber and Schultz (1988) to derive a dosage-effect relationship between outdoor noise exposure and the prevalence of annoyance in communities.
Abstract: : This report applies a NSBIT -developed probabilistic model to a body of social survey findings described by Fidell, Barber and Schultz (1988) to derive a dosage-effect relationship between outdoor noise exposure and the prevalence of annoyance in communities. The probabilistic model (Fidell, Schultz and Green, 1988) provides a means for independently estimating the contributions of acoustic and nonacoustic factors (the latter collectively termed 'response bias') to the observed prevalence of annoyance in communities. The results of the analysis described in this report permit construction of tools that environmental planners can use to make more sophisticated and defensible predictions of annoyance associated with noise of Air Force flight operations. Keywords: Annoyance; Aircraft noise; Traffic noise; Psycho-acoustics; Community response; Noise pollution.
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01 Jan 1989
TL;DR: In this paper, an acoustic antenna system based on the measurement of the spatial correlation function of the sound field along the antenna is presented. But it cannot distinguish between the various sources of interest, since such a high directivity cannot be obtained with conventional directional microphones.
Abstract: In the Netherlands, being a very populated country, noise pollution from industry is of mayor importance. In order to protect the community against severe noise levels due to industry, the immission levels are not allowed to exceed certain values. To verify if these levels are not too high, it is often necessary to measure the immission levels near dwelling areas. However, with conventional sound measuring equipment, only the total immission levels are found and the individual noise sources cannot be distinguished. The measurement sites can be at distances of several 100 m to more than 1 km from the industrial area of concern. Because of these large measurement distances it is necessary to have a high directivity of not more than a few degrees, to be able to distinguish between the various sources of interest. It must be noted that such a high directivity cannot be obtained with conventional directional microphones. Such devices have directivities of not better than about 60 degrees. For that reason we decided to develop SYNTACAN, an acoustic antenna system, based on the measurement of the spatial correlation function of the soundfield along the antenna [1]. The antenna consists of a sparsed array of 32 microphones, positioned in a row over a length of nearly 80 m. It has a theoretical resolving power of 1.5 ± 0.5° over a frequency range from 90 to 1400 Hz.