The review provides an overview of epidemiological studies that were carried out in the field of community noise and cardiovascular risk. The studies and their characteristics are listed in the tables. Risk estimates derived from the individual studies are given for 5 dB(A) categories of the average A-weighted sound pressure level during the day. The noise sources considered in the studies are road and aircraft noise. The health endpoints are mean blood pressure, hypertension and ischaemic heart disease, including myocardial infarction. Study subjects are children and adults. The evidence of an association between transportation noise and cardiovascular risk has increased since the previous review published in Noise and Health in the year 2000.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

Traffic noise is the most important source of environmental annoyance. According to the Environmental Expert Council of Germany, severe annoyance persistent over prolonged periods of time is to be regarded as causing distress. Previously, extraaural noise effects were mostly assessed using a paradigm in which the sound level played the major role. On the basis of this paradigm the relatively low sound level of environmental noise was not considered to be a potential danger to health. In contrast to this numerous empirical results have shown long­term noise-induced health risks. Therefore a radical change of attitude - a change of paradigm - is necessary. For an immediate triggering of protective reactions (fight/flight or defeat reactions) the information conveyed by noise is very often more relevant than the sound level. It was shown recently that the first and fastest signal detection is mediated by a subcortical area - the amygdala. For this reason even during sleep the noise from aeroplanes or heavy goods vehicles may be categorised as danger signals and induce the release of stress hormones. In accordance with the noise stress hypothesis chronic stress hormone dysregulations as well as increases of established endogenous risk factors of ischaemic heart diseases have been observed under long-term environmental noise exposure. Therefore, an increased risk of myocardial infarction is to be expected. The results of individual studies on this subject in most cases do not reach statistical significance. However, according to the Environmental Expert Council, these studies show a consistent trend towards an increased cardiovascular risk if the daytime immission level exceeds 65 dB(A). Most of the previous studies on the extraaural effects of occupational noise have been invalidated by exposure misclassifications. In future studies on health effects of noise a correct exposure assessment is one of the most important preconditions.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

In recent years, the measurement of stress hormones including adrenaline, noradrenaline and cortisol has been widely used to study the possible increase in cardiovascular risk of noise exposed subjects. Since endocrine changes manifesting in physiological disorders come first in the chain of cause-effect for perceived noise stress, noise effects in stress hormones may therefore be detected in populations after relatively short periods of noise exposure. This makes stress hormones a useful stress indicator, but regarding a risk assessment, the interpretation of endocrine noise effects is often a qualitative one rather than a quantitative one. Stress hormones can be used in noise studies to study mechanisms of physiological reactions to noise and to identify vulnerable groups. A review is given about findings in stress hormones from laboratory, occupational and environmental studies.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

Studies on the association between community noise and cardiovascular risk were subjected to a meta-analysis for deriving a common dose-effect curve. Peer-reviewed articles, objective assessment of exposure and outcome as well as control for confounding and multiple exposure categories were all necessary inclusion criteria. A distinction was made between descriptive (cross-sectional) and analytical (case-control, cohort) studies. Meta-analyses were carried out for two descriptive and five analytical studies for calculating a pooled dose-effect curve for the association between road traffic noise levels and the risk of myocardial infarction. No increase in risk was found below 60 dB(A) for the average A-weighted sound pressure levels during the day. An increase in risk was found with increasing noise levels above 60 dB(A) thus showing a dose-response relationship. A risk curve was estimated for the association using a polynomial fit of the data that can be used for risk assessment and the environmental burden of disease calculations.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

In principle, the noise/stress hypothesis is well understood: Noise activates the pituitary­adrenal-cortical axis and the sympathetic-adrenal-medullary axis. Changes in stress hormones including epinephrine, norepinephrine and cortisol are frequently found in acute and chronic noise experiments. The catecholamines and steroid hormones affect the organism's metabolism. Cardiovascular disorders are especially in focus for epidemiological studies on adverse noise effects. However, not all biologically notifiable effects are of clinical relevance. The relative importance and significance of health outcomes to be assessed in epidemiological noise studies follow a hierarchical order, i.e. changes in physiological stress indicators, increase in biological risk factors, increase of the prevalence or incidence of diseases, premature death. Decision-making and risk management rely on quantitative risk assessment. Epidemiological methods are the primary tool for providing the necessary information. However, the statistical evidence of findings from individual studies is often weak. Magnitude of effect, dose-response relationship, biological plausibility and consistency of findings among studies are issues of epidemiological reasoning. Noise policy largely depends on considerations about cost­effectiveness, which may vary between populations. Limit or guideline values have to be set within the range between social and physical well-being - between nuisance and health. The cardiovascular risk is a key-outcome in non-auditory noise effects' research because of the high prevalence of related diseases in our communities. Specific studies regarding critical groups, different noise-sources, day/evening/night comparisons, coping styles and other effect­modifying factors, and the role of annoyance as a mediator of effect are issues for future research in this field.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

Individual animals and humans show differing susceptibility to noise damage even under very carefully controlled exposure conditions. This difference in susceptibility may be related to unknown genetic components. Common experimental animals (rats, guinea pigs, chinchillas, cats) are outbred-their genomes contain an admixture of many genes. Many mouse strains have been inbred over many generations raeducing individual variability, making them ideal candidates for studying the genetic modulation of individual susceptibility. Erway et al. (1993) demonstrated a recessive gene associated with early presbycusis in the C57BL/6J inbred mouse. A series of studies have shown that mice homozygous for Ahlallele are more sensitive to the damaging effects of noise. Recent work has shown that mice homozygous for Ahl are not only more sensitive to noise, but also are probably damaged in a different manner by noise than mice containing the wild-type gene (Davis et al., 2001). Recent work in Noben-Trauth's lab (Di Palma et al., 2001) has shown that the wild-type Ahl gene codes for a hair cell specific cadherin. Cadherins are calcium dependent proteins that hold cells together at adherins junctions to form tissues and organs. The cadherin of interest named otocadherin or CDH23, is localized to the stereocillia of the outer hair cells. Our working hypothesis, suggests that otocadherin may form the lateral links between stereocilia described by Pickles et al (1989). Reduction of, or missing otocadherin weakens the cell and may allow stereocilia to be more easily physically damaged by loud sounds and by aging.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

This paper addresses the negative effects resulting from the exposure to road traffic noise on people's well being with a focus on annoyance. Following the observations that noise exposures engender physiological reactions typical of stress, the non-auditory effects of noise on humans are generally viewed as being stress-related, and annoyance is one of the first and most direct reactions to environmental noise. In general terms, it is found that the continuous exposure of people to road traffic noise leads to suffering from various kinds of discomfort thus reducing appreciably the number of their well being elements. However drawing such a conclusion is hindered by difficulties when non-acoustical factors like sensitivity, socio-economic situation and age are also taken into account along with the usual acoustical factors of road traffic noise. The results of several decades of research on this topic have permitted lately to establish a quantitative relationship between the objective quantities characterizing road traffic noise, namely the day to night noise level, and the human subjective reaction to it as expressed by the percentage of highly annoyed people. These findings are important at both the society and the individual level in as much as they may help in regulating in a more efficient way the planning of road traffic activity in order to secure minimum comfort to the affected population.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

Traffic noise, which is steadily increasing, is considered to be an important environmental health problem. The aim of this study was to estimate the degree of annoyance and sleep disturbance related to road traffic noise in residential settings in an urban community. The study is based on a questionnaire on environmentally related health effects distributed to a stratified random sample of 1000 individuals, 19-80 years old, in a municipality with heavy traffic in the county of Stockholm. The response rate was 76%. The individual noise exposure was estimated using evaluated noise dispersion models and local noise assessments. Frequent annoyance was reported by 13% of subjects exposed to Leq 24 hr >50 dBA compared to 2% among those exposed to <50 dBA, resulting in a difference of 11% (95% Confidence Interval (CI) 7%, 15%). Sometimes or frequently occurring sleep disturbance was reported by 23% at Leq 24 hr >50 dBA and by 13% at levels <50 dBA, a difference of 11% (95% CI 4%, 18%). A positive exposure- response relation was indicated for annoyance as well as for sleep disturbances when classifying the individuals into four different exposure categories (< 45, 46­ 50, 51-55 and >55 dBA Leq 24 hr). There was some habituation to noise for problems related to sleep but not for annoyance. The prevalence of both annoyance and sleep problems was higher when bedroom windows were facing streets. People living in apartments had more sleep problems compared to people living in detached or semi-detached houses. In conclusion traffic noise exposure, even at low levels, was associated with annoyance and sleep disturbance. Access to a quiet side seemed to be a major protective factor for noise related problems.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

Low frequency noise, the frequency range from about 10Hz to 200Hz, has been recognised as a special environmental noise problem, particularly to sensitive people in their homes. Conventional methods of assessing annoyance, typically based on A-weighted equivalent level, are inadequate for low frequency noise and lead to incorrect decisions by regulatory authorities. There have been a large number of laboratory measurements of annoyance by low frequency noise, each with different spectra and levels, making comparisons difficult, but the main conclusions are that annoyance of low frequencies increases rapidly with level. Additionally the A-weighted level underestimates the effects of low frequency noises. There is a possibility of learned aversion to low frequency noise, leading to annoyance and stress which may receive unsympathetic treatment from regulatory authorities. In particular, problems of the Hum often remain unresolved. An approximate estimate is that about 2.5% of the population may have a low frequency threshold which is at least 12dB more sensitive than the average threshold, corresponding to nearly 1,000,000 persons in the 50-59 year old age group in the EU-15 countries. This is the group which generates many complaints. Low frequency noise specific criteria have been introduced in some countries, but do not deal adequately with fluctuations. Validation of the criteria has been for a limited range of noises and subjects.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

It seems to be a common opinion among researchers within the field of audiology that the prevalence of tinnitus will increase as a consequence of environmental factors, for example exposure to loud noise. Young people are exposed to loud sounds, more than any other age group, especially during leisure time activities, i.e. at pop concerts, discotheques and gyms. A crucial factor for the prevention of hearing impairments and hearing-related symptoms in the young population is the use of hearing protection. The focus of the present study is use of hearing protection and self-reported hearing-related symptoms, such as tinnitus and noise sensitivity in a young population of high-school students (N=1285), aged 13 to 19 years. The results show that the prevalence of permanent tinnitus and noise sensitivity, reported in the total group, was 8.7% and 17.1% respectively. Permanent tinnitus was not significantly related to level of socio-economic status, but age-related differences in the prevalence rates of experienced tinnitus and noise sensitivity were found to be significant. Older students reported such symptoms to a greater extent than younger students did. Those who reported tinnitus and other hearing-related symptoms protected their hearing to the highest extent and were the ones most worried.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

Classical musicians are often exposed to sound levels that exceed the Finnish national action limit value of 85 dB(A). Still, the use of hearing protectors is uncommon among musicians. The purpose of this study was to find out musician's attitudes towards hearing protectors, and under which conditions hearing protectors are used. The study group consisted of five major classical orchestras in the Helsinki region. The players were asked to fill out a questionnaire with questions on hearing protection, ear symptoms, including tinnitus, hearing loss, pain in the ears, and temporary ringing in the ears. Also, questions concerning stress and working environments were asked. Of those who responded, 94% were concerned about their hearing to some degree. Only 6% of the musicians always used hearing protector devices (HPDs). Self-­reported hearing loss was quite common, with 31% of the musicians reporting some hearing loss. Temporary tinnitus was even more common at 37%. There were 15% of women, and 18% of men reporting permanent tinnitus. Hyper-acusis was reported by 43% of the musicians. The ear symptoms affected the usage rate. Hearing protectors were used more often among musicians having ear symptoms (20%) than those reporting no symptoms (6%). Further, the 43% of the musicians found their work to be interesting and meaningful. Stress was experienced to some extent by 60%, and musicians with ear symptoms had three to nine times more stress and felt their working environment noisier. The study shows that musicians seldom use hearing protectors before symptoms begin. Symptoms increased usage rate, but the usage levels are still far from ideal. Motivation and training is needed to improve hearing protector use among musicians.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

Noise is a health risk. The only scientifically established adverse health effect of noise is noise­induced hearing loss (NIHL). Besides noise may affect quality of life and cause annoyance and sleep disturbance. The present scientific evidence of potential non-auditory effects of noise on health is quite weak. Whether health promotion works in relation to noise may be reflected by permanent hearing threshold shift development in population studies. Hearing impairment continues to be the most prevalent disability in Western societies. The National Institute of Occupational Safety and Health (NIOSH) still rates noise induced hearing loss among the top ten work-related problems. Recent studies report that employees continue to develop noise induced hearing loss although to a lesser extent than before, in spite of occupational hearing conservation programmes. Besides socio-acusis and leisure noise seem to be an increasing hazard to hearing, also in young children and adolescents. This seems partly related to acute leisure noise exposure (e.g. toy pistols, amplified music). However, population studies increasingly find non­normal high-frequency hearing including the characteristic NIHL-"notch" around 6kHz also in subjects who do not report noise exposure incidents or activities. Today 12.5% of US children 6-19 years show a noise-"notch" in one or both ears (n= 5249, Niskar et al 2001). A Norwegian county audiometry survey on adults > 20 years (n=51.975) showed mean unscreened thresholds +10dB at 6kHz for both genders even for the youngest age group 20-24 years (Borchgrevink et al 2001). Accordingly, the present health promotion initiatives seem insufficient in relation to noise and noise-induced hearing loss.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

The permanently open auditory channel and the ability of the brain to process incoming acoustical stimuli even while asleep and to respond adequately is the essential precondition for noise-induced sleep disturbances which are regarded as the most deleterious effects of noise. In the past, research was mainly focused on the detection and description of the various effects of noise, on the influence of personal and environmental factors, on the determination of dose ­response relations and the definition of critical noise loads, above which noise becomes intolerable. These limits are, however, as yet only tentative or applicable for a very few situations and need to be verified or revised. The present paper is focused on the priorities for future research. These are in particular 1) the causal linkage between environmental noise, primary and secondary effects on the one hand and the hypothesized contribution to multifactorial chronic diseases, to chronic annoyance, and to permanent behavioral alterations on the other hand, 2) the identification of the causes for the great discrepancies between the small effects determined in the field and the large responses recorded in the laboratory, 3) temporal aspects such as sleep at unusual times (day sleep after nightshifts), definition of night-time and day-time, 4) the significance of the shoulder hours for subsequent sleep, 5) the individual vulnerability, 6) the accumulation of data from different studies.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

Impulse noise causes evidently more severe hearing loss than steady state noise. The additional effect of occupational impulse noise on hearing has been shown to be from 5 to 12 dB at 4 kHz audiometric frequency. Reported cases for compensated for hearing loss are prevalent in occupations where noise is impulsive. For impulse noise two measurement methods have been proposed: the peak level method and energy evaluation method. The applicability of the peak level method is difficult as even the recurrent impulses have different time and frequency characteristics. Various national risk criteria differ from international risk criteria. In France the maximum A-weighted peak level is 135 dB, and in the United Kingdom the C-weighted peak sound pressure is limited to 200 Pa (140 dB). This criterion of unweighted 200 Pa (140 dB) is used in European Union (EU) directive 86/188 and ISO 1999-1990 regardless of the number of impulses. The American Conference of Governmental Industrial Hygienists (ACGIH) has recommended that no exposure in excess of a C-weighted peak sound pressure level of 140 dB should be permitted. At work places these norms do not cause any practical consequences since the impulses seldom exceed 140 dB peak level. In several occupations the impulses are so rapid that they contribute only a minimal amount to the energy content of noise. These impulses can damage the inner ear even though they cause reduced awareness of the hazard of noise. Based to the present knowledge it is evident that there is the inadequacy of the equal energy principle in modelling the risk for hearing loss. The hearing protectors attenuate industrial impulse noise effectively due to the high frequency contents of impulses. Directive regarding the exposure of workers to the risks arising from noise requires that in risk assessment attention should be paid also to impulsive noise. So far there is no valid method to combine steady state and impulse noise. A statistical method for the measurements of industrial impulse noise is needed to get a preferably single number for risk assessment. There is an urgent task to develop risk assessment method and risk criteria for impulsive noise to meet the requirements of the upcoming European Union noise directive.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

The focus of the present study, of 1285 adolescents, was young people's attitudes towards noise and their use of hearing protection at discos and pop concerts. Comparisons were made between adolescents from different age groups, and with different socio-economic status. Logistic regressions indicated that "worry before attending noisy activities" and "hearing symptoms" such as tinnitus and noise sensitivity could, to some degree, explain the use of hearing protection in noisy environments. Another conclusion to be drawn from this study was that adolescents' attitudes and behaviors regarding hearing protection use differed between levels of socio-economic status. Individuals with high SES expressed more negative attitudes and used ear protection to a greater extent than those with lower SES. This result might indicate differences in the development of future auditory problems among individuals with different levels of socio-economic status. The cause of hearing impairment and tinnitus may not be restricted merely to noise exposure. Psychological aspects, such as attitudes towards noisy environments and the individual's behavior regarding the use of hearing protection may be considered as important factors in the understanding of why the prevalence of hearing­ related problems has increased among adolescents.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

There is increasing evidence that at least one function of both the medial and the lateral olivocochlear efferent systems is to provide adjustment of the set point of activity in their post­synaptic target, the outer hair cells and afferent processes, respectively. New results, summarized in this review, suggest that both efferent systems can provide protection from noise through this mechanism. There are also intracellular pathways that can provide protection from noise-induced cellular damage in the cochlea. This review also summarizes new results on the pathways that regulate and react to levels of reactive oxygen species in the cochlea as well as the role of stress pathways for the heat shock proteins and for neurotrophic factors in protection, recovery and repair.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

The contradictory and confusing results in noise research on humans may partly be due to individual differences between the subjects participating in different studies. This review is based on a twelve year research on the role of neuroticism, extroversion and subjective noise sensitivity during mental work in noisy environment. Neurotic persons might show enhanced "arousability" i.e. their arousal level increases more in stress. Additional unfavorable factors for neurotics are worrying and anxiety, which might prevent them coping successfully with noise, or some other stressors during mental performance. In numerous experiments introverts have showed higher sensitivity to noise during mental performance compared to extroverts, while extroverts often cope with a boring task even by requesting short periods of noise during performance. Correlation analyses have regularly revealed a highly significant negative relation between extroversion and noise annoyance during mental processing. Numerous studies have shown that people with high noise sensitivity may be prevented from achieving the same work results as other people in noisy environment, thus leading to psycho­somatic, neurotic or other difficulties. Positive relation between noise annoyance and subjective noise sensitivity might be very strong. Our results have shown, after matching with the results of other relevant studies, that more stable personality, with extroversive tendencies and with a relatively lower subjective noise sensitivity measured with standard questionnaires, may be expected to better adapt to noise during mental performance, compared to people with opposite personality traits.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

When planning the development or reduction of large traffic facilities, acoustic calculation procedures are used to forecast the noise load in the affected residential areas. Then, existing dose/response relationships for steady state situations are used to predict noise effects in future years. Planners often assume that (1) noise annoyance reactions of residents do not change over the years, and (2) annoyance is not affected by the change itself. Both of these assumptions are questioned in this paper, and a procedure for estimating future annoyance in changed noise situations is proposed. This includes the analysis of possible statistical trends of the annoyance reactions over the years - even for steady-state noise loads, and with changing state situations, the effects of the change should also be accounted for

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

The present paper provides the results from two nation-wide telephone surveys conducted in Canada on a representative sample of 5,232 individuals, 15 years of age and older. The goals of this study were to gauge Canadians' annoyance towards environmental noise, identify the source of noise that is viewed as most annoying and quantify annoyance toward this principal noise source according to internationally accepted specifications. The first survey revealed that nearly 8% of Canadians in this age group were either very or extremely bothered, disturbed or annoyed by noise in general and traffic noise was identified as being the most annoying source. A follow-up survey was conducted to further assess Canadians' annoyance towards traffic noise using both a five-item verbal scale and a ten-point numerical scale. It was shown that 6.7% of respondents indicated they were either very or extremely annoyed by traffic noise on the verbal scale. On the numerical scale, where 10 was equivalent to "extremely annoyed" and 0 was equivalent to "not at all annoyed", 5.0% and 9.1% of respondents rated traffic noise as 8 and above and 7 and above, respectively. The national margin of error for these findings is plus or minus 1.9 percentage points, 19 times out of 20. The results are consistent with an approximate value of 7% for the percentage of Canadians, in the age group studied, highly annoyed by road traffic noise (i.e. about 1.8 million people). We found that age, education level and community size had a statistically significant association with noise annoyance ratings in general and annoyance specifically attributed to traffic noise. The use of the International Organization for Standardization/Technical Specification (ISO/TS)-15666 questions for assessing noise annoyance makes it possible to compare our results to other national surveys that have used the same questions.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

56 children age 7 - 10 had a medical check-up and they and their mothers completed questionnaires. Additionally the children's excretion of free cortisol was measured by HPLC in two urine samples collected at 1 p.m. and in the morning. The children lived either at a busy road with 24 h lorry traffic or in quiet areas. At the side of the road the noise level was registered during five nights. In the bedrooms representative measurements of the short-term maximal sound level (L _Amax and L _Cmax ) and of the frequency spectrum were taken. During the night on average every 2 minutes a lorry with L _max > 80 dB(A) passed by the houses. The indoor levels of the higher exposed half of the children were L _max = 33-52 dB(A) resp. 55­-78dB(C)). The frequency spectrum had its maximum below 100 Hz. 74% of the higher exposed never opened their windows as compared to 25% in the lower exposed half group. The excretion of free cortisol and its metabolites in the first half of the night was significantly correlated to L _Cmax (co-variables: age, sex, and the day of the week) as well as to impaired sleep, memory and ability to concentrate. The cortisol excretion in the second half of the night was not correlated to the noise level. Disturbances of the normal circadian rhythm of cortisol can be quantified by the quotient of the cortisol excretion in the first half of the night in relation to that in the second half. Children under long-term road traffic noise exposure during the night had an increased risk of chronic stress hormone regulation disturbances. These disturbances were significantly correlated to L _Cmax and findings of allergy and/or asthma bronchial. Long-term low frequency noise exposure with Lmax < 55 dB(A) during the night resulted in chronic increases of children's excretion of free cortisol in the first half of the night and in serious disturbances of the circadian rhythm of cortisol. Indications of increased risks of asthma bronchial and allergies in noise exposed children with stress hormone regulation disturbances need further clarification

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

A lifetime of exposure to noise is likely to have negative effects on the hearing, but the interaction between noise-induced hearing loss (NIHL) and age-related hearing loss is difficult to determine. The most commonly accepted assumption is a simple accumulating effects of noise and ageing on the hearing. However, both a less than additive effect as well as a supra­additive effect has been proposed. Recently an interesting interaction between NIHL and age­related hearing loss has been reported (Gates et al., 2000). NIHL before old age reduces the effects of ageing at noise-associated frequencies, but accelerates the deterioration of hearing in adjacent frequencies. Findings from the longitudinal and cross-sectional gerontological and geriatric population study of 70-year-olds in Gothenburg, Sweden supports these observations. The incidence of tinnitus increases in old age, but not at the same high rate as presbyacusis. According to the gerontological and geriatric population study in Gothenburg tinnitus in old age is related more to hearing loss than to ageing. There are no simple correlations between exposure to noise during the active years and tinnitus in old age.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

A cross-sectional study was performed on a 5% sample of the adult population of the city of Pancevo (3622 residents). The response rate was 79 % (2874), with 1243 interviewed males (43%) and 1631 females (57%). Noise annoyance was assessed on a five- grade verbal scale (Not at all; Slightly; Moderately; Very; Extremely). Arterial hypertension was defined by antihypertensive treatment, information on which was obtained from questionnaire. Myocardial infarction was also subjectively confirmed. Prevalence and odds ratios of arterial hypertension and myocardial infarction were computed for subjects who were very much and extremely annoyed by noise, or moderately annoyed, using residents who were slightly annoyed or not annoyed at all as a referent category. Significant odds ratios (adjusted for age, body mass index and smoking habits) were found for self-reported arterial hypertension [1,8 (1,0-2,4 - 95% confidence interval) , P < 0,01] and myocardial infarction [1,7 (1,0 - 2,9), P < 0,05] in very much or extremely noise disturbed male subjects, compared to those who were not annoyed at all, or were slightly annoyed by noise. The respective odds ratios for females were lower and not statistically significant 1,1 (0,8-1,7) and 1 (0,4 - 2,0).

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

The human perception of sound at frequencies below 200 Hz is reviewed. Knowledge about our perception of this frequency range is important, since much of the sound we are exposed to in our everyday environment contains significant energy in this range. Sound at 20-200 Hz is called low-frequency sound, while for sound below 20 Hz the term infrasound is used. The hearing becomes gradually less sensitive for decreasing frequency, but despite the general understanding that infrasound is inaudible, humans can perceive infrasound, if the level is sufficiently high. The ear is the primary organ for sensing infrasound, but at levels somewhat above the hearing threshold it is possible to feel vibrations in various parts of the body. The threshold of hearing is standardized for frequencies down to 20 Hz, but there is a reasonably good agreement between investigations below this frequency. It is not only the sensitivity but also the perceived character of a sound that changes with decreasing frequency. Pure tones become gradually less continuous, the tonal sensation ceases around 20 Hz, and below 10 Hz it is possible to perceive the single cycles of the sound. A sensation of pressure at the eardrums also occurs. The dynamic range of the auditory system decreases with decreasing frequency. This compression can be seen in the equal-loudness-level contours, and it implies that a slight increase in level can change the perceived loudness from barely audible to loud. Combined with the natural spread in thresholds, it may have the effect that a sound, which is inaudible to some people, may be loud to others. Some investigations give evidence of persons with an extraordinary sensitivity in the low and infrasonic frequency range, but further research is needed in order to confirm and explain this phenomenon.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

The pathogenesis of allergies can be stimulated by adjuvant effects - i.e. air pollutants such as NO ₂ and particles from diesel exhausts as well as noise - the latter especially during night-time. During sleep, noise signals which are associated with danger (i.e. lorry noise) have the potential to trigger stress reactions even if the noise level is low. Increases of cortisol in the first half of the night seem to play an important role. In a blind interview study, the combined effects of chronic exposure to traffic related air pollution and noise, upon the risk of skin and respiratory diseases in children were studied. All children between 5-12 years, who had consulted one of two participating paediatricians were included in the study. The paediatricians diagnoses of 400 children were analysed together with their parents answers regarding the density of road traffic on their street and several confounding factors. Multiple regression analyses resulted in relative risks of asthma, chronic bronchitis and neurodermitis, which increased significantly with increasing traffic load. A comparison with the literature on such effects caused by air pollution alone, showed that traffic noise during the night might have an adjuvant effect on the pathogenesis of the mentioned diseases.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]

Many jobs at the Department of Fisheries and Oceans Canada (DFO) have several features in common: they are often performed in noisy environments and involve a number of auditory skills and abilities, such as speech communication, sound localization, and sound detection. If an individual lacks these skills and abilities, it may constitute a safety risk for this individual, as well as for fellow workers and the general public. A number of scientific models have been developed to predict performance on these auditory skills based on diagnostic measures of hearing such as pure-tone audiograms. While these models have significant scientific and research value, they are unable to provide accurate predictions of real life performance on auditory skills necessary to perform hearing-critical jobs. An alternative and more accurate approach has been developed in this research project. A direct measure of functional speech perception in noise (Hearing in Noise Test: HINT) has been identified and validated for use in screening applicants for hearing-critical jobs in DFO. This screening tool has adequate and well-defined psychometric properties (e.g. reliability, sensitivity, and validity) so that screening test results can be used to predict an individual's ability to perform critical auditory skills in noisy environments, with a known degree of prediction error. Important issues must be considered when setting screening criteria. First, the concept of hearing-critical tasks must be reviewed, since these tasks are often performed in high noise levels where normally-hearing people cannot hear adequately. Second, noise-induced hearing loss is frequent in these noisy environments, and workers who acquire a hearing loss might not continue to meet the minimal auditory screening criteria throughout their career. Other senses (e.g., vision, touch) also play an important role in these environments. Third, adaptation strategies have to be considered when recruits or incumbents fail the screening test.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]  [PubMed]