Noise health effects are the physical and psychological health consequences of regular exposure to consistent elevated sound levels. Noise from traffic, in particular, is considered by the World Health Organization to be one of the worst environmental stressors for humans, second only to air pollution. Elevated workplace or environmental noise can cause hearing impairment, tinnitus, hypertension, ischemic heart disease, annoyance, and sleep disturbance. Changes in the immune system and birth defects have been also attributed to noise exposure.
Although age-related health effects (presbycusis) occur naturally with age, in many countries the cumulative impact of noise is sufficient to impair the hearing of a large fraction of the population over the course of a lifetime.Senate Public Works Committee, Noise Pollution and Abatement Act of 1972, S. Rep. No. 1160, 92nd Cong. 2nd session Noise exposure has been known to induce noise-induced hearing loss, tinnitus, hypertension, vasoconstriction, and other cardiovascular adverse effects. Chronic noise exposure has been associated with sleep disturbances and increased incidence of diabetes. Adverse cardiovascular effects occur from chronic exposure to noise due to the sympathetic nervous system's inability to habituate. The sympathetic nervous system maintains lighter stages of sleep when the body is exposed to noise, which does not allow blood pressure to follow the normal rise and fall cycle of an undisturbed circadian rhythm.
Stress from time spent around elevated noise levels has been linked with increased workplace accident rates, aggression, and other anti-social behaviors. The most significant sources are vehicles, aircraft, prolonged exposure to loud music, and industrial noise. Prolonged exposure to noise at home has been linked to decreased mental health.
There are approximately 10,000 deaths per year as a result of noise in the European Union.
Noise-induced hearing loss
Noise-induced hearing loss is a permanent shift in pure-tone thresholds, resulting in sensorineural hearing loss. The severity of a threshold shift is dependent on duration and severity of noise exposure. Noise-induced threshold shifts are seen as a notch on an audiogram from 3000 to 6000 Hz, but most often at 4000 Hz.
Exposure to loud noises, either in a single traumatic experience or over time, can damage the auditory system and result in hearing loss and sometimes tinnitus as well. Traumatic noise exposure can happen at work (e.g., loud machinery), at play (e.g., loud sporting events, concerts, recreational activities), and/or by accident (e.g., a backfiring engine). Noise-induced hearing loss is sometimes unilateral and typically causes patients to lose hearing around the frequency of the triggering sound trauma.
Tinnitus Tinnitus is an auditory disorder characterized by the perception of a sound (ringing, chirping, buzzing, etc.) in the ear in the absence of an external sound source. There are two types of tinnitus: subjective and objective. Subjective is the most common and can only be heard "in the head" by the person affected. Objective tinnitus can be heard from those around the affected person and the audiologist can hear it using a stethoscope. Tinnitus can also be categorized by the way it sounds in one's ear, pulsatile tinnitus which is caused by the vascular nature of Glomus tumors and non-pulsatile tinnitus which usually sounds like crickets, the sea and bees.
Though the pathophysiology of tinnitus is not known, noise exposure can be a contributing factor; therefore tinnitus can be associated with hearing loss, generated by the cochlea and central nervous system (CNS). High-frequency hearing loss causes a high-pitched tinnitus and low-frequency hearing loss causes a roaring tinnitus. Noise-induced tinnitus can be temporary or permanent depending on the type and amount of noise a person was exposed to.
Cardiovascular effects Noise has been associated with important cardiovascular health problems, particularly hypertension, as it causes an increase in levels of stress hormones and vascular oxidative stress. Noise levels of 50 dB(A) or greater at night may increase the risk of myocardial infarction by chronically elevating cortisol production.
Traffic noise has several negative effects, including increased risk for coronary artery disease, with night-time exposure to noise possibly more harmful than day-time exposure. It has also been shown to increase blood pressure in individuals within the surrounding residential areas, with railways causing the greatest cardiovascular effects. Roadway noise levels are sufficient to constrict arterial blood flow and lead to elevated blood pressure. Vasoconstriction can result from elevated adrenaline levels or through medical stress reactions. Long-term exposure to noise is correlated to an increase in cortisol and angiotensin-II levels which are respectively associated with oxidative stress and vascular inflammation. Individuals subject to greater than 80 dB(A) in the workplace are at increased risk of having increased blood pressure.
A 2021 systematic review on the effect of occupational exposure to noise on ischemic heart disease (IHD), stroke and hypertension, coordinated by the World Health Organization (WHO) and the International Labour Organization (ILO) located 17 studies that met the inclusion criteria, comprising a total of 534,688 participants (7.47% females) in 11 countries and in three WHO regions (the Americas, Europe, and the Western Pacific). The study found the low quality of evidence the effect of occupational exposure to intense noise (≥85 dBA), compared to occupational exposure below 85 dBA (<85 dBA). They concluded that there is inadequate evidence of harmfulness for the studied outcomes with the exception of the risk of acquiring IHD, which was 29% higher for those exposed to noise in their workplace.
Other physical health effects Traffic noise may also increase the risk of sleep disturbances, stroke, diabetes, and becoming overweight. Noise pollution is an environmental health concern since it is often a risk factor for developing other diseases like tinnitus or impaired speech discrimination.Basner, M., Babisch, W., Davis, A., Brink, M., Clark, C., THE LANCET, Volume 383, issue 9925(April, 2014), page 1325-1332.
Psychological impacts of noise Causal relationships have been discovered between noise and psychological effects such as annoyance, psychiatric disorders, and effects on psychosocial well-being. Exposure to intense levels of noise can cause personality changes and violent reactions. Noise has also been shown to be a factor attributed to violent reactions. The psychological impacts of noise also include an addiction to loud music. This was researched in a study where non-professional musicians were found to have loudness addictions more often than non-musician control subjects.
Psychological health effects from noise also include depression and anxiety. Individuals who have hearing loss, including noise-induced hearing loss, may have their symptoms alleviated with the use of hearing aids. Individuals who do not seek treatment for their loss are 50% more likely to have depression than their aided peers. These psychological effects can lead to detriments in physical care in the form of reduced self-care, work-tolerance, and increased isolation.
Auditory stimuli can also serve as psychological triggers for individuals with post traumatic stress disorder (PTSD).
Stress Research commissioned by Rockwool, a multi-national insulation manufacturer headquartered in Denmark, reveals that in the UK one third (33%) of victims of domestic disturbances claim that loud parties have left them unable to sleep or made them stressed in the last two years. Around one in eleven (9%) of those affected by domestic disturbances claims it has left them continually disturbed and stressed. More than 1.8 million people claim noisy neighbours have made their life a misery and they cannot enjoy their own homes. The impact of noise on health is potentially a significant problem across the UK given that more than 17.5 million Britons (38%) have been disturbed by the inhabitants of neighbouring properties in the last two years. For almost one in ten (7%) Britons this is a regular occurrence.
The extent of the problem of noise pollution for public health is reinforced by figures collated by Rockwool from local authority responses to a Freedom of Information Act (FOI) request. This research reveals that in the period April 2008 – 2009 UK councils received 315,838 complaints about noise pollution from private residences. This resulted in environmental health officers across the UK serving 8,069 noise abatement notices, or citations under the terms of the Anti-Social Behaviour (Scotland) Act.
Westminster City Council has received more complaints per head of population than any other district in the UK with 9,814 grievances about noise, which equates to 42.32 complaints per thousand residents. Eight of the top 10 councils ranked by complaints per 1,000 residents were in London.
Annoyance Sudden impulse noises are typically perceived as more bothersome than noise from traffic of equal volume.Miedema and Oudshoorn 2001 cited in Annoyance effects of noise are minimally affected by demographics, but fear of the noise source and sensitivity to noise both strongly affect the 'annoyance' of a noise. Sound levels as low as 40 dB(A) can generate noise complaints and the lower threshold for noise producing sleep disturbance is 45 dB(A) or lower.
Other factors that affect the annoyance level of sound include beliefs about noise prevention and the importance of the noise source, and annoyance at the cause (i.e., non-noise-related factors) of the noise. Many of the interpretations of the level of annoyance and the relationship between noise levels and resulting health symptoms could be influenced by the quality of interpersonal relationships at the workplace, as well as the stress level generated by the work itself. Evidence for impact on annoyance of long-term noise versus recent changes is uncertain.
Approximately 35% to 40% of office workers find noise levels from 55 to 60 dB(A) extremely irritating. The noise standard in Germany for mentally stressful tasks is set at 55 dB(A), however, if the noise source is continuous, the threshold level for tolerability among office workers is lower than 55 dB(A).
Child physical development The U.S. Environmental Protection Agency authored a pamphlet in 1978 that suggested a correlation between low-birthweight (using the World Health Organization definition of less than ) and high sound levels, and also high rates of birth defects in places where expectant mothers are exposed to elevated sound levels, such as typical airport environments. Specific birth abnormalities included harelip, cleft palate, and defects in the spine.Noise: A Health Problem United States Environmental Protection Agency, Office of Noise Abatement and Control, Washington, D.C. 20460, August, 1978
According to Lester W. Sontag of The Fels Research Institute (as presented in the same EPA study): "There is ample evidence that environment has a role in shaping the physique, behavior, and function of animals, including man, from conception and not merely from birth. The fetus is capable of perceiving sounds and responding to them by motor activity and cardiac rate change." The effects of noise exposure are highest when it occurs between 15 and 60 days after conception, a period in which major internal organs and the central nervous system are formed.