Noise - 2,325 entradas encontradas

Sus criterios de búsqueda son

• Noise

1988

CIS 91-2035 Acoustics - Determination of sound power levels of noise sources - Engineering methods for special reverberation test rooms
Acoustique - Détermination des niveaux de puissance acoustique émis par les sources de bruit - Méthodes d'expertise en salles réverbérantes spéciales [en francés]
This international standard specifies relatively simple engineering methods for determining the weighted and octave-band sound power levels of small noise sources. The methods are not suitable for noise sources which emit impulsive noise consisting of single noise bursts. Contents: definitions; test room requirements; instrumentation; installation and operation of source; measurement of noise emitted by source; calculation of sound power levels. Annexes include characteristics and calibration of a reference sound source.
International Organization for Standardization, Case postale 56, 1211 Genève 20, Switzerland, 12 Jan. 1988. iii, 19p. Illus. 14 ref.

CIS 91-2034 Acoustics - Determination of sound power levels of noise sources - Precision methods for discrete-frequency and narrow-band sources in reverberation rooms
Acoustique - Détermination des niveaux de puissance acoustique émis par les sources de bruit - Méthodes de laboratoire en salles réverbérantes pour les sources émettant des bruits à composantes tonales et à bande étroite [en francés]
This international standard specifies the special requirements necessary for accurate determinations of the sound power of a source which radiates discrete frequencies or narrow bands of noise. Details are given of the determination of the significance of discrete-frequency components and narrow bands of noise, and of the additional microphone positions and source locations required. All other requirements are the same as for broad-band sources described in ISO 3741.
International Organization for Standardization, Case postale 56, 1211 Genève 20, Switzerland, 12 Jan. 1988. iii, 8p. 14 ref.

CIS 91-2023 Talamo J.D.C., Staynes R.M., Smith D.W., Baker N.R.
A review of agricultural tractor noise test procedures and measured levels
This report examines available information on noise levels at the operator's position on agricultural tractors subjected to test according to the OECD tractor performance testing code and Council Directive 77/311/EEC (see CIS 77-1593) relating to driver-perceived noise levels of tractors. Technical problems that might result from the adoption of more stringent limit values than those specified in the Directive are reviewed and cost implications discussed. Differences between the OECD code and the EEC Directive are also examined. Recommendations include a reduction in required test levels for cabs to 87dB(A) within 2 years and 85dB(A) within 5 years.
Health and Safety Executive, St. Hugh's House, Stanley Precinct, Trinity Road, Bootle, Merseyside L20 3QY, United Kingdom, 1988. 34p. Illus. 15 ref. Price: GBP 20.00.

CIS 91-2022 Leventhall H.G., Wong L.
A review of active attenuation and development of an active attenuator 'open refuge'
Active attenuation is attracting increasing attention as a possible way of controlling noise in situations where conventional measures have proved inadequate. This report introduces the basic principles of active attenuation and reviews its development and the situations where it has been applied. Practical problems and limitations likely to be encountered in its use are described, and requirements for the future development of more effective systems are discussed. A laboratory attempt to control noise exposure in an open refuge is also described.
Health and Safety Executive, St. Hugh's House, Stanley Precinct, Trinity Road, Bootle, Merseyside L20 3QY, United Kingdom, 1988. 124p. Illus. 51 ref. Price: GBP 25.00.

CIS 91-290 Giménez de Paz J.G.
Materiales fonoabsorbentes porosos: Modelo predictivo
An equation describing resistance to fluid flow was found to be applicable to the attenuation of sound by porous materials: α = a+b log(t)+c log(d), where α is the coefficient of sound absorption in percent, t is the thickness of the material in millimeters and d is its density in kg/m³; a, b and c are empirical constants that were evaluated in experiments with 13 samples of glass wool. The equation gave good predictions of the performance of other samples, and may be applicable to other materials.
Mapfre seguridad, 4th quarter 1988, No.32, p.37-42. 12 ref. Illus.

CIS 90-1925 Zaborov V.I., Kljačko L.N., Rosin G.S.
Noise and vibration control in the iron and steel industry
Zaščita ot šuma i vibracii v černoj metallurgii [en ruso]
The book is intended for engineers and technical staff engaged in the iron and steel industry and in machinery production. Contents: noise effects on production personnel (basic concepts and relationships, sound pressure level determination at workplaces, determination of the required noise reduction); noise reduction at source (mechanical and aerodynamic noise); noise control measures (sound isolation, sound absorption, silencers, antivibration mountings); noise control in different production plants (mining, sintering, steelmaking, rolling, metalware production, refractory and ferroalloy production, cake and by-product process, service shops, personal protective equipment); vibration effects on production personnel (basic concepts and relationships, vibration health effects, exposure assessment and regulation); vibration isolation design (basic concepts, calculations for major structures, design of vibration insulators); vibration control measures for working with hand pneumatic and impact tools, grinders, die-forging and forging hammers, vibration isolation at workplaces, economic efficiency of vibration control measures.
Izdatel'stvo Metallurgija, 2 Obydenskij per. 14, 119857 Moskva, USSR, 1988. 214p. Illus. 100 ref. Price: SUR 0.85.

CIS 90-2039 Kjellberg A., Landström U., Löfstedt P., Wide P., Åkerlund E.
Estimation of perceived discomfort from noise at work - A methodological study
Bedömning av upplevd bullerstörning i arbetet - En metodstudie [en sueco]
Report describing a field study of the correlation between occupational exposure to noise and annoyance. 142 measurements of noise were made in different types of work environments. The noise was analysed and described in terms of dB(A), dB(B), dB(C), dB(D) and dB(Lin). Subjective response to the noise was analysed with the help of a questionnaire. The questionnaire included subjective ratings of annoyance responses to occupational noise and to verbally described reference noises. The results of the investigation showed the importance of calibrating individual ratings and that a verbally described noise can be used for such a calibration. A-levels did not in any case produce a better prediction of annoyance than any of the other weighting methods.
Arbetsmiljöinstitutet, Förlagstjänst, 171 84 Solna, Sweden, 1988. 36p. Illus. 9 ref.

CIS 90-1870 Hempstock I.
Unit: Harmful noise - Module: Basic principles
Training module designed for home study. It includes many practical exercises with answers. There are two segments: 1 - Basic acoustics (sound waves; the decibel system; sound power; frequency analysis; energy equivalent level; percentage exceedance levels; noise rating curves); 2 - hearing (the human ear; measurement of hearing and performance of the ear; age and frequency response of the ear; loudness; hearing damage).
Occupational Health and Safety, Portsmouth Polytechnic, Lion Gate Building, Lion Terrace, Portsmouth PO1 3HF, United Kingdom, 1988. 38p.

CIS 90-2047 Sass-Kortsak A.M.
Workplace noise and noise measurement. A basic guide
Le bruit au travail et la mesure du bruit - Guide de base [en francés]
This publication, in the form of questions and answers, explains the nature of workplace noise and basic measurement techniques. It is useful for people taking simple noise measurements, or reviewing the results of noise surveys. It does not discuss the effects of workplace noise on people or the methods of control.
Canadian Centre for Occupational Health and Safety, 250 Main St. East, Hamilton, Ontario L8N 1H6, Canada, Dec. 1988. 18p. Illus. 9 ref.

CIS 90-2084 Landström U., Törnros J., Nilsson L., Morén B., Söderberg L.
Interactions between noise, temperature, wakefulness and performance analysed in a simulator study
Samband mellan vakenhetsmått och prestationsmått erhållna vid körsimulatorstudie avseende effekter av buller och temperatur [en sueco]
Correlation analyses were carried out on the effects of noise and temperature on wakefulness and performance of subjects driving a simulator. Wakefulness was analysed through electroencephalographs and performance through recording of speed-holding, road-holding and braking. A positive correlation in time was observed between EEG, pulse and performance. The result is discussed with respect to the interaction between exposure to high levels of infrasound and fatigue and exposure to high levels of high frequency noise and alertness.
Arbetsmiljöinstitutet, Förlagstjänst, 171 84 Solna, Sweden, 1988. 18p. Illus. 6 ref.

CIS 90-1574 Ginzburg D.A., Lagutina T.S., Petina L.V., Čemnyj A.B.
Electrophysiological investigation of the central and peripheral nervous system in workers exposed to ultrasound
Ėlektrofiziologičeskie issledovanija central'noj i periferičeskoj nervnoj sistemy u rabotajuščih v kontakte s ul'trazvukom [en ruso]
Electroencephalographic (EEG) and electromyographic (EMG) changes were studied in workers operating ultrasonic non-destructive testing equipment. EEG data for 129 operators (4 men and 125 women, aged 19-47 years with exposure histories of 2 to 20yrs) displaying symptoms of vegetative hand polyneuritis showed the percentage of operators with EEG changes to range from 57 to 87% depending on length of exposure (length of service up to 8yrs). Stimulant and local electromyography demonstrated objectively the existence of vegetative hand polyneuritis in non-destructive testing equipment operators, while revealing in some of them disturbances of motor function control. Comparative analysis of the EEG and EMG data suggested that the observed deviations in various EMG parameters, symptoms of hand polyneuritis, and functional cerebral disorders developed independently of each other.
Gigiena truda i professional'nye zabolevanija, July 1988, No.7, p.45-46. 4 ref.

CIS 90-1678 Genuit K.
Artificial-head measurement technique - a new procedure for classification and analysis of noise
Kunstkopf-Messtechnik - Ein neues Verfahren zur Geräuschdiagnose und -analyse [en alemán]
For assessing the irritation due to noise, subjects listen to recordings made through the ears of an artificial head. Through the use of filters, those parts of the frequency spectrum which are most annoying can be identified. The method was applied to motor vehicle engine, gear and tyre noise and other noise sources.
Lärmbekämpfung, 1988, Vol.35, No.4, p.103-108. Illus. 7 ref.

CIS 90-1677 Grohmann R.
Studies of the pathophysiological effects of noise on the vestibular apparatus
Untersuchungen zur Pathophysiologie des Gleichgewichtsorgans bei Lärmeinwirkung [en alemán]
Two groups of subjects with 5 years of occupational exposure to noise levels exceeding 90dB(A) and an unexposed control group were subjected to nystagmographic analyses. Of the exposed group, 120 suffered from minor and 114 from major permanent hearing loss in the high frequency range. No significant vestibular disorders could be detected in either of the exposed groups. Nevertheless, since subjects were exposed only to high frequency noise, the question whether balance can be affected by low frequency noise remains open.
Lärmbekämpfung, 1988, Vol.35, No.4, p.91-96. 15 ref.

CIS 90-1691 Probst W.
Bundesanstalt für Arbeitsschutz
Sound radiation and sound propagation - Calculation models and sound power determination
Schallabstrahlung und Schallausbreitung. Berechnungsmodelle und Schalleistungsbestimmung [en alemán]
This report describes modules for the numerical evaluation of the radiation and propagation of sound emitted by machines in industrial buildings. The modules use the image source modelling technique with and without any tracing for acoustically smooth surfaces as well as a scanning method for acoustically rough surfaces. The inclusion of big structures in radiation screening effects and angle-dependent absorption enable the calculation of the sound pressure level in machinery layouts.
Wirtschaftsverlag NW, PF 101110, 2850 Bremerhaven 1, Federal Republic of Germany, 1988. 272p. 44 ref.

CIS 90-1699 Noise reduction at web-fed presses
This booklet provides details of available noise control options and their implementation in web-fed presses used for newspaper and general printing. All new press installations should incorporate adequate noise control measures such as improved press design to reduce noise generation, quiet areas for remote control of operations, and reduction of reverberant noise levels in machine rooms. Noise control measures for existing presses include total press enclosure, a partial enclosure by acoustic screens, quiet corridors and havens to protect working positions, and enclosure of the folder, usually the noisiest part of the press. Ear protectors should be worn and employees trained in their maintenance and use. Legal requirements for noise control are outlined and case studies illustrate how noise reduction methods have been used in practice.
HMSO Books, P.O. Box 276, London SW8 5DT, United Kingdom, 1988. 27p. Illus. Bibl. Price: GBP 4.90.

CIS 90-1177
Branchesikkerhedsrådet
General information on noise
Generelt om støj [en danés]
Contents of this training booklet giving practical advice on noise at the workplace: the prevalence of harmful noise at work in Denmark, hearing damage, other harmful effects, relevant provisions of Danish OSH legislation, unnecessary noise, the use of hearing protection, preventive measures and noise reduction, plant safety organisation and the purchase of new machines. A list of relevant Danish legislation, directives and standards is appended.
Arbejdsmiljøfondet, Vermundsgade 38, 2100 København Ø, Denmark, 1st ed., 1988. 11p. Illus. 4 ref.

CIS 90-774 Parahonskij Ė.V.
Occupational safety and health in quarries
Ohrana truda na kar'erah [en ruso]
Contents of this training manual written for vocational training school students: general aspects; fundamentals of Soviet OSH legislation; OSH organisation; occupational injuries and diseases; general requirements for the protection of workers and environment at the stage of quarry design and operation; workplace climate and microclimate; noxious dust and gas control; workplace lighting; radiation protection; safety of the main processes; safety of the pressure vessels and systems, hoisting and lifting equipment and repair work; electrical safety; fire safety; flood and snow-drift control; mine rescue fundamentals.
Izdatel'stvo Nedra, pl. Belorusskogo vokzala 3, 125047 Moskva, USSR, 1988. 197p. Illus. 14 ref. Price: SUR 0.30.

CIS 90-998 Schaffert E.
Bundesanstalt für Arbeitsschutz
Noise control by design XV. Control of sludge suction vehicle noise
Lärmarmkonstruieren XV - Lärmminderung an Saugfahrzeugen [en alemán]
This report is of a research project on noise reduction measures concerning sludge-suction vehicles used in street cleaning. The sound power of the vehicles was determined by different methods. Starting from comprehensive measurements, a ranking of the noise sources was performed, which is the foundation of the noise-reducing measures described. The measures presented in the report resulted in the reduction of the sound pressure level by 20-78dB(A). In addition, the A-weighted sound power could be reduced by 19dB(A).
Wirtschaftsverlag NW, Postfach 101110, 2850 Bremerhaven 1, Federal Republic of Germany, 1988. 131p. Illus. 5 ref.

CIS 90-983 Mayer S., Schönherr E.
Secondary noise control measures for hydraulic units - New approaches to silent operation
Sekundärmassnahmen dienen der Lärmbekämpfung bei Hydraulikgeräten - Neue Wege für leise Arbeit [en alemán]
An anechoic chamber is described which is used in identifying noise sources in hydraulic equipment. Outlined design modifications of a hydraulic pump concern optimisation of pressure pulsations. Sound level reductions of 2-3dB(A) were achieved. Noise levels of a hydraulic lifting device were lowered by 10-12dB(A) through sound absorbing and insulating measures.
Industrie-Anzeiger, 1988, Vol.110, No.65, p.10-12. Illus. 2 ref.

CIS 90-982 Noise reduction by selection of machines with low sound emission - cooled circular saws
Lärmminderung durch Auswahl leiser Maschinen - Kaltkreissägemaschinen [en alemán]
A diagram is presented plotting the A-weighted sound levels of cooled, metalcutting, circular saws as function of the nominal motor power. It represents the results of extensive sound level measurements of cooled circular saws in operation in the Federal Republic of Germany. Best available low-noise tools have sound levels below the 25-percentile line in the diagram.
Amtliche Mitteilungen der Bundesanstalt für Arbeitsschutz, Oct. 1988, No.4, p.6-7. Illus.

CIS 90-812 Varsek Z.
Improved well-being - Floor covering which improves thermal insulation and reduces noise in industrial workshops
Wohlbefinden gesteigert - Verbessern der Wärmedämmung und des Schallschutzes mit Hilfe von Industriebodenplatten [en alemán]
With low-cost floor panels made of recycled asbestos-free insulating material from used cables, sound levels and heat loss in workshops can be reduced. The floor panels are easy to apply and are extremely resistant to wear and chemical spills. They do not give off air pollutants. Examples of industrial applications are presented.
Maschinenmarkt, 1988, Vol.94, No.40, p.62-65. Illus.

CIS 90-1038 Welzl-Müller K., Stephan K.
Speech recognition performance with hearing aids with and without background noise
Sprachverständlichkeit mit Hörgerät - ohne und mit Störschall [en alemán]
The influence of hearing aids on the speech intelligibility threshold (i.e. the sound pressure level required to understand 50% of spoken words) without background noise and on the required signal-to-noise ratio was studied on 199 men and 93 women aged 40 to 85 years. It was found that hearing aids improved speech intelligibility but had no influence on the signal-to-noise ratio.
Audiologische Akustik - Audiological Acoustics, 1988, Vol.27, No.4, p.108-114, 119. Illus. 14 ref.

CIS 90-785 Beranek L.L.
Noise and vibration control
Revised and updated version of the 1971 textbook (CIS 73-624). It can be used by persons with no special training in acoustics. Chapters: the behaviour of sound waves; levels, decibels and spectra; sound and vibration transducers; field measurements - equipment and techniques; data analysis; the measurement of power levels and directivity patterns of noise sources; sound propagation outdoors; sound in small spaces; sound in large rooms; acoustical properties of porous materials; interaction of sound waves with solid structures; mufflers; isolation of vibrations; damping of panels; wrappings, enclosures and duct lining; noise of gas flows; damage risk criteria for hearing; criteria for noise and vibration in communities, buildings and vehicles. Appendices: general references; English system of units; conversion factors; decibel conversion tables.
Institute of Noise Control Engineering, P.O. Box 3206, Arlington Branch, Poughkeepsie, NY 12603, USA, rev. ed. 1988. 672p. Illus. Bibl. ref. Price: USD 38.00.

CIS 90-617 Kurumatani N., Iki M., Moriyama T., Ishikawa H., Adachi S., Satoh M., Arai T.
Cross-sectional study of blood pressure and electrocardiograms of forestry workers exposed to both noise and local vibration
The blood pressure and electrocardiograms of 953 forestry workers using vibrating tools were investigated to study the chronic effect of noise and local vibration on the cardiovascular system. The mean systolic blood pressure of the workers was significantly higher than that of a comparable population. But there was no association between blood pressure and the total operation time of chain saws. The bradycardia rate was 2-5 times higher in the subject population that in the general Japanese population. This was considered to be an adaptive response to an increase in oxygen demand while working in the forest. Although there were no results suggesting a relationship between noise, local vibration and cardivascular system, operators with vibration-induced white fingers showed a significantly higher prevalence of atrical fibrillation than those without.
Industrial Health, 1988, Vol.26, No.1, p.43-54. Illus. 53 ref.

CIS 90-501 Kobryn U., Rothe R., Meister A., Bräuer D., Kreibich H.
Reaction of the cardiovascular system, TTS and sensations during local dynamic muscular work and noise
Reaktion des Herzkreislaufsystems, TTS und Befindlichkeit bei lokaler dynamischer Muskelarbeit unter Lärmeinwirkung [en alemán]
Ten male and ten female subjects aged 30 to 39 years were exposed to noise of 90dB(A) without muscular work and to noise (90 dB(A)) combined with one-hand work. The reactions of the cardiovascular system were higher during the combined exposure (noise and one-hand work) than during comparable local muscular work without noise. There were also differences in changes of cardiovascular parameters and temporary threshold shift of hearing (TTS) in men and women. The noise sensitivity index seems to reflect physical changes in the body during and after acute noise exposure.
Zeitschrift für die gesamte Hygiene und ihre Grenzgebiete, July 1988, Vol.34, No.7, p.415-417. Illus.

CIS 90-282 Stapel A.G.
Valve reduces noise of pneumatic angle grinders - Primary noise reduction
Abluftventil verringert Geräuschentwicklung an Druckluft-Winkelschleifern - Primärer Gehörschutz [en alemán]
A valve controlling the flow of exhaust air from grinding machines reduced noise levels to well below 90dB(A). Peak levels during starting and stopping were, in particular, reduced. The valve keeps a constant pressure at all airflows and grinding speeds.
Humane Produktion - Humane Arbeitsplätze, 1988, Vol.10, No.8, p.28-29. Illus.

CIS 89-2012 Lalande N.M., Lambert J., Riverin L.
Development of questionnaires for occupational hearing loss victims and their spouses
Développement de questionnaires pour les victimes de surdité professionnelle et leur conjoint [en francés]
The hearing handicap and the needs for rehabilitation services cannot be predicted from a pure tone audiogram. The use of interviews or questionnaires is necessary to evaluate the psychosocial disadvantages experienced in daily life, or to plan appropriate interventions to reduce the handicap. Various qustionnaires have been developed in the United States and in Europe. In order to use them with a French-speaking population, however, they would have to be translated and adapted. Moreover, these questionnaires were not designed specifically (a) to identify those persons most susceptible of experiencing disadvantages due to occupational hearing loss; (b) to promote the self-acknowledgement of a hearing problem by the hearing impaired and their relatives; and (c) to favour the willingness to enroll in a rehabilitation program. Within the framework of a community health intervention, these objectives are crucial. The validation of a French experimental questionnaire has allowed us to propose two questionnaires, one related to the screening of handicap due to occupational hearing loss and the other to the evaluation of the psychosocial disadvantages experienced by the workers and their close relatives.
Travail et santé, Autumn 1988, Vol.4, No.3, p.S20-S25. Bibl.

CIS 89-1550 Strasser H.
Radiation exposure from monitors and effects on hearing of high-frequency tones at workplaces in television and film production studios
Zur Strahlenbelastung durch Monitore und zu Auswirkungen von Pfeiftönen auf die Hörfähigkeit an Arbeitsplätzen im Fernseh- und Filmbereich [en alemán]
The radiation measured at a distance of 5cm from visual display units is 0.2mR/h. Thus, the quarterly radiation dose operators are exposed to is 0.5rem. In the Federal Republic of Germany the permissible quarterly radiation dose for women is 1.5rem. For men it is 3rem. A similar comparison for high-frequency tones in film studios yielded no noise exposure that would lead to hearing impairment.
Zentralblatt für Arbeitsmedizin, Arbeitsschutz, Prophylaxe und Ergonomie, 1988, Vol.38, No.6, p.170-176. Illus. 30 ref.

CIS 89-1678 Neumann H.D., Sterzl M.
Noise exposure of garbage collectors
Lärmimmission bei der Arbeit des Müllwerkers [en alemán]
Noise exposure of garbage collectors over an 8-h work period was determined with the aid of 3 microphones attached to the helmet, shoulder and ear of each worker. Noise signals were recorded and integrated to 8-h averages. Even in communities with long travelling distances and a low number of garbage cans emptied per day, average exposure levels above 90dB(A) were obtained.
Sicherheitsingenieur, 1988, Vol.19. No.7, p.38-43. Illus.

CIS 89-1441 Second enforcing order on the fourth ordinance of the Law on the Environment - Limitation of noise emission of products [German Democratic Republic]
Zweite Durchführungsbestimmung zur vierten Durchführungsverordnung zum Landeskulturgesetz - Begrenzung der Lärmemission von Erzeugnissen - vom 14. Januar 1988 [en alemán]
Provisions for the observance of control limits on the design and operation of plants, machinery, vehicles, building installations and consumer durables. Entry into force: 1 March 1988.
Gesetzblatt der Deutschen Demokratischen Republik, 8 Feb. 1988, Part I, No.3, p.26-27.

CIS 89-1674 Koetsier J.
Reduction of noise annoyance at gas pressure control stations
Begrenzung von Lärmbelästigungen an Gasstationen [en alemán]
A noise attenuator for gas pressure control stations made of porous NiCr-alloy is described. In the numerous pores of the attenuator, gas expansion and pressure reduction take place gradually which reduces turbulance and therefore noise production. Measurements prior to and after installation of the noise attenuator yielded a sound pressure level drop from 91 to 61dB(A).
Chemie-Anlagen und Verfahren, May 1988, Vol.21, No.5, p.111-112. Illus.

CIS 89-1673 Roddewig H., Fechter R.
Acoustic enclosure of the belt drive of a high-capacity excavator
Schallschutzkapsel am Bandantrieb eines Grossbaggers [en alemán]
Among various noise abating measures, an acoustic enclosure of the belt drive with silencers close to the bottom was chosen for reducing the noise of a bucket wheel excavator with a daily output of 240,000m³ in an opencast mine. Estimates yielded a noise reduction by 17dB(A). Measurements using a sound source comparable to the belt drive in loudness revealed a decrease of the noise level outside the enclosure by 12dB(A).
Fördern und Heben, 1988, Vol.38, No.6, p.397-401. Illus. 1 ref.

CIS 89-1690 Mayer S., Schönherr E.
Noise reduction of hydraulic equipment - An engineering task
Lärmminderung bei Hydraulikaggregaten - Eine Aufgabe für den Ingenieur [en alemán]
An anechoic chamber for sound measurements on hydraulic pumps is illustrated. It was used to identify noise emitting sources and to derive primary (design alterations) and secondary (damping, noise absorption) noise abatement measures for positive-displacement pumps. Examples of each are described.
Humane Produktion - Humane Arbeitsplätze, 1988, Vol.10, No.4-5, p.8-11. Illus. 2 ref.

CIS 89-1676 Matschke R.G.
Noise protection and radio communication - A little-regarded contradiction
Lärmschutz und Sprechfunkverkehr - ein wenig beachteter Widerspruch [en alemán]
An active noise compensation circuit is described which neutralises the original noise by reverse-phase noise. The effectiveness of earphones equipped with this circuit in reducing cockpit noise without interference with radio communication signals was studied with the crews of a helicopter and an airplane under real flight conditions. Considerable noise reduction in the low-frequency range was obtained.
Audiologische Akustik - Audiological Acoustics, 1988, Vol.27, No.5, p.166-176. Illus. 23 ref.

CIS 89-1363 Acoustics - Measurement of high-frequency noise emitted by computer and business equipment
Acoustique - Mesurage du bruit à haute fréquence émis par les matériels informatiques et de bureau [en francés]
This international standard specifies 4 methods for the determination of the sound power levels of high-frequency noise emitted by computer and business equipment in the frequency range covered by the octave band centred at 16kHz. They are complementary to the methods described in ISO 7779 (see CIS 88-2055).
International Organization for Standardization, Case postale 56, 1211 Genève 20, Switzerland, 15 Nov. 1988. 11p. Illus.

CIS 89-1362
Health and Safety Commission; Paper and Board Industry Advisory Committee
Protection of hearing in the paper and board industry
This Guidance Note should be read in conjunction with the appropriate parts of the Health and Safety at Work Act 1974 and guidance contained in the 'Code of practice for reducing the exposure of employed persons to noise'. It is intended to help managers, health and safety advisers, buyers, safety representatives, technical staff and employees to reduce noise in their workplace using a step-by-step approach. Advice is given on how to use a noise survey to draw up a plan of action for a hearing conservation programme. The guidance concentrates on giving a practical appreciation of how exposure to excessive noise damages hearing and on providing quick reference to specific noise control measures. Detailed examples of noise reduction techniques are given in tabular format. In appendices: glossary of acoustic terms; legal requirements; methods for determining the adequacy of ear protectors; use of noise dosimeters.
HMSO Publication Centre, P.O. Box 276, London SW8 5DT, United Kingdom, 1988. 40p. Illus. 56 ref. Price: GBP 9.00.

CIS 89-1347 Corkhill A.
Noise attenuation in the factory of the future
By January 1990, legislation will be introduced in all EC member states harmonising each country's standards for the protection of workers from the risks related to exposure to noise at work. This article looks beyond 1990 to a time when new noise criteria are being proposed for manufacturing industry, based not upon hearing conservation alone but also upon the specific need of the employee to concentrate, resolve on-the-spot problems, and be able to talk comfortably to other employees when adjacent to noise-producing equipment; the overall objective being to improve productivity levels on the shop floor.
Noise and Vibration Control, Oct. 1988, Vol.19, No.9, p.252-254. Illus.

CIS 89-725 Protection of workers against noise. Circular letter of 6.5.1988 [France]
Protection des travailleurs contre le bruit. Circulaire du 6.5.1988 [France] [en francés]
Circular letter relating to the application of Decree No. 88-405 of 21 April 1988 (Bulletin officiel du Ministère des affaires sociales et de l'emploi - Travail, emploi, fascicule 88/11). This circular letter comments on the different articles of the decree published in the last Cahier de Notes Documentaires (ND 1697-132-88): general prevention principles, noise exposure control, collective technical prevention and personal protection, staff information and training, special measures applicable to specific tasks. An appendix gives the significance of daily noise exposure levels and of peak noise pressure levels from the physical viewpoint.
Cahiers de notes documentaires - Sécurité et hygiène du travail, 4th Quarter 1988, No.133, Note No. 1710-133-88, p.755-757.

CIS 89-724 Decree No. 88-405 of 21 April 1988 on the protection of workers against noise. Noise measurement. Approval of noise measurement organisations [France]
Décret n°88-405 du 21 avril 1988. Protection des travailleurs contre le bruit. Mesurage du bruit. Modalités d'agrément des organismes de contrôle du bruit [France] [en francés]
Decree No. 88-405 of 21 April 1988 (published in the Journal Officiel of 22 April 1988) modifying the French Labour Code (Part 2: Decrees in the Council of State) and French Government order of 22 April 1988 (published in the Journal Officiel of 10 May 1988). The decree of 21 April covers: general principles of risk prevention, noise exposure monitoring, technical and collective prevention, individual protection, medical surveillance, information and training, certain specific jobs, Labour Inspectorate injunctions, machine noise reduction. The order of 22 April defines noise measurement conditions and the content of the file any organisation applying for government approval must submit to the ministry in charge of labour affairs.
Cahiers de notes documentaires - Sécurité et hygiène du travail, 3rd Quarter 1988, No. 132, Note No. 1697-132-88, p.525-528.

CIS 89-980 Makarewicz G.
A comparative analysis of the possibility of using geometric methods for the description of the acoustic properties of interiors
Analiza porównawcza możliwości stosowania metod geometrycznych do opisu właściwości akustycznych wnętrz [en polonés]
The geometric methods for simulation of the sound field in areas delimited by planes (the image sources method and the ray-tracing method) have not been applied in practice for a long time due to the lack of computational algorithms. The effective application of the image sources method and the ray tracing method demands that a comparative analysis be carried out. An attempt at such an analysis is presented in this article. It shows the superiority of the image sources method in the simulation of real physical phenomena with the acoustic wave propagation in a limited area as well as in the accuracy of the results obtained in the simulation.
Prace Centralnego instytutu ochrony pracy, 1988, Vol.38, No.137, p.95-108. 5 ref.

CIS 89-979 Koton J., Pleban D.
Determination of the sound power of industrial noise sources for ultrasonic frequencies up to 100kHz (II)
Wyznaczanie mocy akustycznej źródeł przemysłowych dla częstotliwości ultradźwiękowych do 100kHz (II) [en polonés]
Results of experimental studies on the distribution of the sound field surrounding industrial installations emitting noise within the frequency range 10-100kHz. The results were analysed and compared with the predictions of acoustic field theory. A method for determining the sound power level and the directionality of industrial sources of ultrasonic noise is presented. A preliminary paper on these studies appeared in Prace CIOP, vol.36, No.128, p.39-53, 1986.
Prace Centralnego instytutu ochrony pracy, 1988, Vol.38, No.137, p.79-94. 16 ref.

CIS 89-978 Self-reported hearing loss among workers potentially exposed to industrial noise - United States
Data collected from approximately 40,000 households as a result of National Health Interview Surveys in 1971 and 1977 have been analysed by the National Institute for Occupational Safety and Health (NIOSH) in order to assess the prevalence of hearing loss among adult workers in the United States. Exposure levels were estimated on the basis of the 1972-74 National Occupational Hazard Survey (NOHS) of approx. 5000 workplaces in the US. Some degree of hearing loss was reported by 3.2% of all respondents. Self-reported hearing loss was higher among adults working in industries with potential exposure. Industries in the manufacturing sector had the highest prevalence of noise exposure (overall exposure rate, 37%). Respondents were divided into three groups: 1) persons with light exposure, or those working in industries where less than 10% of the employees were exposed to noise more or equal to 85dBA; 2) persons with moderate exposure, or those employed in industries where 10-24% of workers received such exposure; 3) persons with heavy exposure, or those employed in industries where more than or equal to 25% of workers received such exposure. A comparison of these groups showed that the prevalence of self-reported hearing loss increased with both age and increasing exposure to industrial noise.
Journal of the American Medical Association, 15 Apr. 1988, Vol.259, No.15, p.2213-2217. 10 ref.

CIS 89-646 Rindel
Contribution to the study of the job of swimming-pool life guards
Contribution à l'étude du poste de maître-nageur sauveteur surveillant de piscine [en francés]
Topics: literature on the subject; clinical examination and testing; analysis of environmental factors (temperature, lighting, chemical substances and microorganisms present). The most important risk factor is noise (exposure to levels over 90dBA).
Cahiers de médecine interprofessionnelle, 2nd Quarter 1988, No.110, p.43-46.

CIS 89-638 Mitani Y., Ota M.
A practical probabilistic evaluation method for the noise reduction effect of sound absorbing materials
This report describes a practical probabilistic evaluation method for the stochastic noise reduction effect when a stationary random noise excitation of arbitrary non-Gaussian distribution type is attenuated by inserting a sound absorbing material into a room. The effectiveness of the proposed method has been confirmed by applying it to the actual noise data observed in a reverberation room. The experimental results are in good agreement with the theoretically predicted curves.
Journal of the Acoustical Society of Japan, May 1988, Vol.9, No.3, p.147-152. Illus. 6 ref.

CIS 89-645 Niemeyer W.H.
Primary noise reduction measures in the woodworking industry: Milling tools
Primäre Lärmminderungsmassnahme in der Holzverarbeitung: Fräswerkzeuge [en alemán]
A multiple-point milling cutter used for woodworking is described. It is lower in noise by 8.8dB(A) when idling and by 7.7dB(A) during operation than the conventional tools. It is characterised by a staggered arrangement of narrow cutting edges on the milling head. The noise-reducing design was developed on the basis of studies of the main noise sources by sound level, sound power measurements and determination of the frequency spectrum.
Industrie-Anzeiger, 1988, Vol.110, No.23, p.40-41. Illus. 2 ref.

CIS 89-269 Haering H.U., Polthier K.
Noise emission and reduction by drop forging shops
Geräuschemission und Lärmminderung von Gesenkschmieden [en alemán]
Sound pressure levels in drop forging shops with one or more drop hammers and different extents of sound insulation (walls, doors, ceilings, ventilation ducts) were determined. The data were used to calculate noise levels inside and outside the drop forging shops. A distance of 25m is required for the noise emitted by small and new forges with extensive sound insulation to drop to 46dB(A). For large forges a distance of 50m is necessary.
Stahl und Eisen, Feb. 1988, Vol.108, No.4, p.179-184. Illus. 8 ref.

CIS 89-261 Shioda M.
Vibration problems of refuse disposal plants
Gomi-shori-shisetsu no shindō-mondai [en japonés]
Description of a refuse collection and incineration plant. Typical levels and frequencies of noise/vibration at different points in the plant are presented, and sources are described. Modelling of conditions at the planning stage enables more effective noise/vibration control.
Journal of the INCE of Japan, Apr. 1988, Vol.12, No.2, p.33-37.

CIS 88-1847 Orlowski R., Baum J., Hempstock I.
Unit: Harmful noise - Module: Noise control
Training module designed for home study. It includes many practical exercises with answers. There are 3 segments: 1 - Principles of noise control (outdoors and indoors noise sources, sound absorption, sound insulation, vibration isolation); 2 - Noise control in practice (noise control by planning and design, at source, by barriers, by enclosure, in rooms, in factories; vibration isolation in practice); 3 - Personal hearing protection (types of hearing protectors, performance and limitations, selection, education).
Occupational Health and Safety, Portsmouth Polytechnic, Department of Design, Lion Gate Building, Lion Terrace, Portsmouth PO1 3HF, United Kingdom, 1988. 165p. Illus. Bibl.

CIS 88-1846 Wright F., Veater T.
Unit: Harmful noise - Module: Legal and organisational aspects of noise
Training module designed for home study. It includes many practical exercises with answers. There are 7 segments: 1 - The noise problem in general; 2 - Outline of the legal framework in England and Wales; 3 - Noise control and the European Communities; 4 - Occupational noise controls (relevant passages from the Factories Act, the Code of Practice for reducing noise exposure at work, and the Health and Safety Act); 5 - Environmental noise controls (Common Law and statutory control); 6 - Civil Law claims and state benefits; 7 - Preparation of proofs of evidence. A study guide is provided for users with specialist needs.
Occupational Health and Safety, Portsmouth Polytechnic, Department of Design, Lion Gate Building, Lion Terrace, Portsmouth PO1 3HF, United Kingdom, 1988. 181p. Illus. Bibl.

CIS 88-1845 Baum J., Shack R.
Unit: Harmful noise - Module: Noise measurement
Training module designed for home study. It includes many practical exercises with answers. There are 3 segments: 1 - Instruments for measuring noise (sound level meters, frequency analysers, tape recorders, level recorders, dosimeters, calibration, choosing equipment); 2 - How to measure noise (preparing a noise survey, measuring personal exposure, measurements to assess nuisance complaints, measurements for noise control, measurements to select hearing protectors, records and reports); 3 - Noise from new plant and equipment (measurements, test environments).
Occupational Health and Safety, Portsmouth Polytechnic, Department of Design, Lion Gate Building, Lion Terrace, Portsmouth, PO1 3HF, United Kingdom, 1988. 112p. Illus.

CIS 88-2051 McMahon K.J., McManus P.E.
Occupational noise exposure in the printing industry
The noise exposures of 274 printing production workers in 34 establishments in the New York City area were monitored. Results showed that 43% were exposed to 8-hr time-weighted average (TWA) noise exposures of 85dBA or greater and that 14% were exposed to 8-hr TWAs of 90dBA or greater. Within the press department, web press workers were exposed to significantly greater mean 8-hr TWAs than sheetfed press workers. In general, a greater percentage of the workers in the bindery departments were exposed to potentially harmful noise than workers in the press departments. Results of this study indicate that many workers in the printing industry may be at risk of occupational hearing loss. Further research is needed to determine the extent of hearing impairment in this group of workers.
American Industrial Hygiene Association Journal, Jan. 1988, Vol.49, No.1, p.34-37. 8 ref.

< anterior | 1... 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 ...47 | siguiente >