Individual Noise Exposure Research Articles

Do ambient noise exposure levels predict hearing loss in a modern industrial cohort?

Background: Much of what is known about the exposure–response relationship between occupational noise exposures and hearing loss comes from cross-sectional studies conducted before the widespread implementation of workplace hearing conservation...

Direct, indirect influences of income on road traffic noise annoyance

Studies of human reactions to noise have often also studied possible impacts of nonacoustic variables such as income, education and occupational status. While such social status variables have been shown to modify health outcomes they do not have any important effect in noise-annoyance studies. However, the socio-acoustic research analyses usually employ regression models where the noise each person is exposed to is regarded as exogenous, i.e given. This precludes the analysis of indirect effects, such as wealthy people buying themselves out of noisy neighbourhoods. To explore this type of indirect effects, the relationship between noise exposure, income and noise annoyance is investigated a step further in this paper. Structural equation models incorporating both direct and indirect pathways have been estimated using data from six socio-acoustic surveys combining individual noise exposure measures with questions on noise perception and background characteristics. The hypothesis that high-income groups buy themselves free from noise is only partly confirmed. It seems to hold true for residents of a small-to-medium size city, but not for residents of a larger city. With respect to income as a possible modifier of annoyance, the previous results that no such moderating effects can be found are confirmed.

Hypertension and Exposure to Noise near Airports (HYENA): study design and noise exposure assessment.

An increasing number of people live near airports with considerable noise and air pollution. The Hypertension and Exposure to Noise near Airports (HYENA) project aims to assess the impact of airport-related noise exposure on blood pressure (BP) and cardiovascular disease using a cross-sectional study design. We selected 6,000 persons (45–70 years of age) who had lived at least 5 years near one of six major European airports. We used modeled aircraft noise contours, aiming to maximize exposure contrast. Automated BP instruments are used to reduce observer error. We designed a standardized questionnaire to collect data on annoyance, noise disturbance, and major confounders. Cortisol in saliva was collected in a subsample of the study population (n = 500) stratified by noise exposure level. To investigate short-term noise effects on BP and possible effects on nighttime BP dipping, we measured 24-hr BP and assessed continuous night noise in another sub-sample (n = 200). To ensure comparability between countries, we used common noise models to assess individual noise exposure, with a resolution of 1 dB(A). Modifiers of individual exposure, such as the orientation of living and bedroom toward roads, window-opening habits, and sound insulation, were assessed by the questionnaire. For four airports, we estimated exposure to air pollution to explore modifying effects of air pollution on cardiovascular disease. The project assesses exposure to traffic-related air pollutants, primarily using data from another project funded by the European Union (APMoSPHERE, Air Pollution Modelling for Support to Policy on Health and Environmental Risks in Europe).

Annoyance with aircraft noise in local recreational areas, contingent on changes in exposure and other context variables.

Few socioacoustic studies have examined the effect of noise on outdoor recreationists. The areas studied have been mountain and wilderness areas that people typically travel for a distance to visit. In this article we examine the reactions to aircraft noise in local recreational areas experiencing either decreased (1930 survey respondents), or increased noise exposure (1001 survey respondents). Field studies were conducted before and after the relocation the main airport of Norway in 1998 in one area near each airport. The relationship between individual noise exposure (LAeq for the aircraft events, percentage of time aircraft were audible, and LAsel) for the aircraft events. The analyses included the "situation" in which data were collected (before or after the relocation), and variables describing the recreational context. A strong effect of the "situation" was found in both cases, but the size of the effect was influenced by the choice of exposure variable in one of the study areas. Other context variables were also influencing annoyance. The effect of the situation (before/after a change in exposure) on the dose-response relationship may be influenced by the initial noise levels, the amount of change, and the time elapsed since the change at the time of the second survey. Further research should investigate the significance of these variables.

Road Traffic Noise Exposure And Myocardial Infarction - A Novel Approach

The aim of this research was to study the risks for myocardial infarction associated with long term exposure to residential road traffic noise exposure using refined epidemiological methods (The ROM study). To control for potential risk factors, a large Swedish population-based case-control study (Stockholm Heart Epidemiology Program [SHEEP]) of first-time myocardial infarction was used for the investigation. Road traffic noise exposure was calculated for a total of 7,700 addresses from 1970 and onwards. A novel approach to assess individual noise exposure over several decades was used to study the relation between longitudinal traffic noise exposure and myocardial infarction.

Continuous noise monitoring and reduction system and method

An apparatus adapted to be worn in an environment in which unsafe noise levels may be present for the purpose of continuously monitoring the noise level impinging upon the ear(s) of a user. The noise levels are monitored via a microphone housed within a hearing protective device, and located such that the noise level measured by the microphone is representative of the noise level impinging upon the ear(s) of the user when the hearing protective device is being worn in either a primary or secondary position. The noise level is recorded along with its duration to calculate a cumulative noise dose for an individual user, and to warn the user of when the noise dose exceeds a preset level. The apparatus further provides for a means of transmitting the noise level and dose information to a data storage/retrieval device such as a PC for maintaining a history of noise exposure for the individual user of the device. A method of using an apparatus as described, or a similar device, to continuously monitor an individual's noise exposure is also disclosed.

ADVERSE HEALTH EFFECTS IN RELATION TO URBAN RESIDENTIAL SOUNDSCAPES

Noise pollution from road traffic in residential areas is a growing environmental problem. New approaches to turn the negative trend are needed. The programme “Soundscape Support to Health” will achieve new knowledge about the adverse health effects of noise pollution on humans and will investigate the link between well-being and health and perceived soundscapes for optimizing the acoustic soundscapes in urban residential areas. This paper will briefly present the programme and presents preliminary results from the first study of how various adverse health effects are related to individual noise exposures among individuals in residential areas with and without access to a quiet side of the dwelling.

Road Traffic Noise Annoyance in Relation to Average Noise Level, Number of Events and Maximum Noise Level

The extent of annoyance caused by road traffic noise was investigated in 15 areas with a varying number of vehicles and different distances between the traffic and houses. The goal was to compare two principles for expressing noise exposure. One was based on the conventional energy equivalent value in terms of a 24-hourLAeqvalue. The other was based on the number of events and noise level as two independent variables. A postal questionnaire study was performed in the different areas, and noise exposure measurements were made at a representative site in each area. The individual noise exposure was calculated on the basis of the distance of the respondent from the road and the floor level. The results showed that the number of noise events did not influence the extent of annoyance. There was a strong relationship between theLAeqand the extent of annoyance as well as between the maximum noise level and the extent of annoyance. These data suggest that actions to control the disturbing effects of road traffic noise should focus on noisy vehicles and that limiting the number of vehicles would not have an effect on the extent of annoyance.

Styrene and Noise Exposures and Protective Equipment Use in the Manufacturing of Fiberglass Products in Canada

Abstract Time-weighted average styrene and noise exposures were assessed for a cohort of 256 workers taken from 13 glass fiber-reinforced plastics manufacturing plants in Canada using conventional methods. Statistically significant differences existed in styrene exposures between the plants, although only 11 percent of the subjects had measured exposures in excess of 50 ppm (213 mg/m3). Few subjects reported using respiratory protection. Open/contact molding techniques were associated with higher exposures than closed molding processes, with those using chopper guns, involved in grid manufacture, and doing manual hand layup in confined spaces having the highest exposures. No differences were observed in styrene exposures between filament winding for pipes less than 0.75 m in diameter compared with large tanks (up to 2 m in diameter) wound on mandrels. The styrene exposures were consistent with, or slightly lower than, those reported in the literature. Individual noise exposures ranged from 70 to 105 dBA, ...

Noise Exposure of Truck Drivers: A Comparative Study

To investigate the extent of noise exposure to which truck drivers are subjected, a comparison was made of the noise levels in the cabs of two different brands of trucks. Both brands were manufactured with identical engines. The equivalent continuous A–weighted sound pressure levels, maximum sound pressure levels, and percentage noise dose were determined. This study sought to determine if truck drivers are exposed to excessive noise inside the cabs of these trucks. Furthermore, the most beneficial working environment in terms of the brand used was investigated. No significant differences regarding the individual noise exposure of the truck drivers were found (P>0.05). Based on comparison of measured noise exposures to existing criteria, it was determined that the noise exposures of truck drivers are potentially hazardous to their hearing.

Noise Exposure of Truck Drivers: A Comparative Study

To investigate the extent of noise exposure to which truck drivers are subjected, a comparison was made of the noise levels in the cabs of two different brands of trucks. Both brands were manufactured with identical engines. The equivalent continuous A-weighted sound pressure levels, maximum sound pressure levels, and percentage noise dose were determined. This study sought to determine if truck drivers are exposed to excessive noise inside the cabs of these trucks. Furthermore, the most beneficial working environment in terms of the brand used was investigated. No significant differences regarding the individual noise exposure of the truck drivers were found (P > 0.05). Based on comparison of measured noise exposures to existing criteria, it was determined that the noise exposures of truck drivers are potentially hazardous to their hearing.

Prospective study of noise exposure during pregnancy on birth weight.

To examine the effect of noise exposure during pregnancy on infant birth weight, a well-characterized cohort of 200 pregnant women in the first trimester participating in prenatal care clinics was followed throughout gestation (in Taiwan, 1991). Individual 24-hour noise exposure of all women was prospectively measured, and information regarding possible noise exposure from traffic and occupation was also obtained. Noise exposure during pregnancy was correlated with the birth weights of the women's babies. No association between personal noise exposure measured in decibels (less than 85 dBALeq during pregnancy) and birth weight was found. Possible occupational noise exposure (indicated by working in a manual job), traffic noise exposure (indicated by distance between the home and main streets), and a history of listening to amplified music and using personal listening devices during pregnancy also showed no effect on infant birth weight. Maternal weight, maternal weight gained during pregnancy, gestational age, and infant's sex were the four factors that correlated significantly with birth weight. The noise exposure experienced by women during pregnancy may not be great enough to affect their infants' birth weight.

A survey on individual noise exposures in a noisy factory.

In order to estimate the individual noise exposure in a factory using several types of hand tools, it is unsatisfactory to measure the sound level emitted from the tools or to simply measure the sound level at various points in the work space. The authors tried to compare the results of a personal noise dosimeter, Rion Co. Ltd., Japan (type : NB-02A), with the results of stationary sound level meters, 10 channel noise dosimeters (Rion, type NA-76) and a digital sound level meter (Rion, type NA-76). Two workshops, welding and repairing by sixteen and fourteen workers respectively, in an airplane repair factory, were surveyed.The personal noise dosimeters were set to measure the time duration exposed equal to or more than 80 dB (A) and were carried individually in the breast pocket of each worker from 10 a.m. to 4 p.m. in the same day. The exposure time data were also given from stationary measurement points.Sound levels of all the hand tools, for example, hand hammer, air grinder, rivett gun, air drill etc., were more than 85 dB (A) at the point of one meter (1 m) apart from the tools. So the sound from the tools will be accumulated from the time when the workers switched them on. The workers used the tools individually, according to the various work processes. Stationary noise measurements showed that 75 dB (A) was L50 in the welding shop, and the duration exposed equal to or more than 80 dB (A) was 109 and 97 minutes at two points. Measurements by the personal noise dosimeters varied from 103 to 221 minutes for twelve workers in the welding shop who used mainly hand tools. A longer term survey on individual noise exposures will give more precise data on the relationship between the noise dose and the noise induced permanent threshold shift of workers.

Application of Some New Survey Techniques for Assessing Exposure to Noise and Human Reaction

The components of human reaction to noise have been studied extensively in the laboratory, but have been less assessed in the real world. This paper describes a theoretical framework and practical application of some novel techniques for assessing human reaction under field conditions. Data collection techniques never before applied in this context included (1) 24-hour diary (recall), and (2) paired-comparison method to determine an individual's relative value of noise/ quiet. These techniques were utilized as part of a survey instrument, or questionnaire, which was administered to a small group of subjects in a preliminary test. The survey was tested in four different residential sites in conjunction with a pilot test of a system for assessing community noise and individual noise exposure and reaction to this exposure. [The study was supported jointly by the Department of Transportation and the Environmental Protection Agency.]

A Technique for Individual Noise Exposure Assessment

Instrumentation and methodologies were developed in a feasibility study to measure noise exposure, at the ear, of a person as he went about his usual daily activities. Two physiological parameters, heart rate, and peripheral vasoconstriction at the earlobe, were also monitored during the same measurement period. The instrumentation consisted of a small, portable package consisting of (1) a subminiature electret microphone worn on the ear, (2) standard EKG chest leads for measuring heart rate, (3) a photoplethysmo-graph sensor mounted on the earlobe for measuring peripheral vasoconstriction, (4) circuitry to convert the microphone signal into a dc voltage proportional to the A -weighted noise level, and (5) a subminiature four-channel cassette tape recorder. Each of the five persons who participated in the experiment were instrumented early in the morning, wore the device for the entire day, and removed it at night (leaving it in the bedroom until it was picked up the next morning). Each person also kept a log of location and activity during the day. Representative results of the pilot study are illustrated by synchronized time history records of the noise levels and physiological responses. The technique could be adapted to allow the measurement of noise exposure and physiological response under a wide variety of circumstances in the field. [The study was supported by the Department of Transportation and the Environmental Protection Agency.]

Noise Dosimetry and Noise Index Calculations

The individual noise exposure for constant sound level conditions, and hence the noise injury risk, can be estimated by conventional measurement of sound intensity, frequency and duration of exposure. The durations of different intensity components of intermittent noise of known periodicity can be easily estimated from noise index calculations such as Swedish Standard SEN 590111. For intermittent exposure where the noise source varies in an uncontrolled manner, or when the exposed person moves between different noise zones, the total exposure can be recorded by the personal noise dosimeter which instantaneously integrates sound pressure and duration of exposure.28 noise dosimeters type SRA 71 have been exposed to 100 dB “white noise” under standardized conditions. The results show good agreement between dosimeters and for the same dosimeter on different occasions. A nomogram has been prepared for converting the total noise dose to an equivalent sound level in dB(A).The Swedish norms are based on tables wh...

System for the Measurement of Noise Exposure

To evaluate the noise exposure on the flight deck of aircraft carrier, a system has been developed that gives a statistical description of the noise experienced by personnel involved in the launching of jet aircraft. The system utilizes a small portable FM transmitter that can be easily carried about the flight deck to monitor an individual's noise exposure. The signal received from this transmitter is recorded on magnetic tape and, at a later time, analyzed by means of a device called the “Cumulator.” The Cumulator measures the total time that the intensity level of the noise exceeds each of seven preset levels. The Cumulator has three separate channels, each capable of analyzing a different position of the frequency spectrum. Typical cumulative distributions of the noise exposure for flight-deck personnel will be presented.