Noise health effects are the physical and mental health problems that happen when people are regularly exposed to loud and constant sounds. Noise from traffic, in particular, is considered by the World Health Organization to be one of the most harmful environmental stressors for humans, second only to air pollution. Loud noises in workplaces or the environment can lead to hearing loss, ringing in the ears, high blood pressure, heart disease, feelings of annoyance, and trouble sleeping. Changes in the immune system and birth defects have also been linked to noise exposure.

Although hearing loss from aging (called presbycusis) happens naturally over time, in many countries, the long-term effects of noise are serious enough to cause hearing problems in a large number of people during their lifetime. Exposure to loud noises can cause hearing loss, ringing in the ears, high blood pressure, narrowed blood vessels, and other problems with the heart and blood vessels. Long-term noise exposure has been connected to sleep issues and a higher chance of developing diabetes. These heart-related problems happen because the body’s stress response system cannot get used to constant noise. This system keeps the body in a lighter sleep stage when noise is present, which stops blood pressure from following its normal daily pattern.

Stress from being around loud noises for long periods has been linked to more workplace accidents, anger, and other harmful behaviors. The biggest sources of noise are vehicles, planes, loud music played for long times, and industrial sounds. Being exposed to loud noises at home has been connected to worse mental health.

About 10,000 people die each year in the European Union due to noise-related health problems.

Noise induced hearing loss

Noise-induced hearing loss is a lasting change in how well a person can hear certain sounds. This type of hearing loss happens when the inner ear is damaged by loud noises. The amount of hearing loss depends on how long and how loud the noise was. On a hearing test called an audiogram, this kind of hearing loss often shows up as a dip in hearing ability between 3,000 and 6,000 Hz, most commonly around 4,000 Hz.

Loud noises can harm the hearing system, leading to hearing loss and sometimes ringing in the ears called tinnitus. This damage can occur from a single very loud event, such as a loud explosion, or from repeated exposure to loud sounds over time. Examples of situations that can cause this include working near loud machines, attending loud events like concerts or sports games, or experiencing unexpected loud noises like a car backfiring. This type of hearing loss may affect only one ear and usually causes trouble hearing sounds near the frequency of the noise that caused the damage.

Tinnitus

Tinnitus is a hearing problem in which a person hears sounds such as ringing, chirping, or buzzing in their ears even when no actual sound is present. There are two main types of tinnitus: subjective and objective. Subjective tinnitus is the most common type and is only heard by the person experiencing it. Objective tinnitus can be heard by others nearby and by a doctor using a stethoscope. Tinnitus can also be divided into two categories based on the type of sound heard. Pulsatile tinnitus is linked to blood vessel issues, such as those caused by Glomus tumors, and often sounds like a heartbeat. Non-pulsatile tinnitus usually sounds like crickets, the ocean, or bees.

The exact cause of tinnitus is not fully understood, but exposure to loud noises may contribute to its development. Tinnitus is often connected to hearing loss, which can occur in the inner ear or the central nervous system. Hearing loss in high frequencies typically causes a high-pitched tinnitus, while hearing loss in low frequencies often results in a low, roaring sound. Tinnitus caused by loud noises can be temporary or permanent, depending on how loud the noise was and how long the person was exposed to it.

Cardiovascular effects

Noise has been linked to serious heart and blood vessel problems, especially high blood pressure. This happens because noise raises levels of stress hormones and causes stress in blood vessels. Noise levels of 50 dB(A) or higher at night may increase the risk of heart attacks by keeping cortisol levels high over time.

Traffic noise can harm health in many ways, including increasing the risk of disease in the arteries that carry blood to the heart. Exposure to noise at night may be more harmful than during the day. Studies show that noise from traffic can raise blood pressure in people living nearby, with train noise causing the greatest effects. Road noise can narrow blood vessels and increase blood pressure. Narrowing of blood vessels may happen due to high adrenaline levels or stress reactions. Long-term noise exposure is connected to higher levels of cortisol and angiotensin-II, which are linked to stress in the body and inflammation in blood vessels. People exposed to noise levels above 80 dB(A) at work are more likely to have higher blood pressure.

A 2021 review by the World Health Organization (WHO) and the International Labour Organization (ILO) studied the effects of workplace noise on heart disease, stroke, and high blood pressure. The review included 17 studies with over 534,000 participants from 11 countries across three WHO regions. The studies found that evidence about the effects of workplace noise (85 dB(A) or higher) was of low quality compared to noise below 85 dB(A). The review concluded that there was not enough evidence to prove harm from workplace noise for most health issues, except for a 29% higher risk of ischemic heart disease in people exposed to loud noise at work.

Other physical health effects

Traffic noise can lead to problems like trouble sleeping, stroke, diabetes, and being overweight. Noise pollution is a health issue in the environment because it can contribute to other problems such as tinnitus or difficulty in understanding speech.

Psychological impacts of noise

Noise can cause psychological effects such as annoyance, mental health problems, and issues with how people interact socially. Being exposed to very loud noise for long periods may lead to changes in personality and sudden, aggressive behavior. Research has shown that loud noise can also be linked to a habit of listening to very loud music. A study found that people who are not professional musicians are more likely to develop a strong preference for loud music compared to people who are not musicians.

Noise can also lead to feelings of sadness, known as depression, and worry, known as anxiety. People with hearing loss, including hearing loss caused by loud noise, may benefit from using hearing aids. Those who do not use hearing aids are about twice as likely to experience depression compared to those who do. These mental health effects can harm physical health by reducing self-care, lowering the ability to work, and increasing loneliness.

For people with post traumatic stress disorder (PTSD), certain sounds can act as triggers that cause strong emotional or physical reactions.

Stress

A study funded by Rockwool, a company that makes insulation and is based in Denmark, shows that in the UK, one-third (33%) of people who experience domestic disturbances report that loud parties have made it hard for them to sleep or caused them stress in the past two years. About one in eleven (9%) of those affected say they have been constantly disturbed and stressed. More than 1.8 million people say noisy neighbors have made their lives difficult and prevented them from enjoying their homes. Noise can have a major effect on health in the UK, as more than 17.5 million Britons (38%) say they have been disturbed by neighbors in the past two years. For nearly one in ten (7%) Britons, this is a regular problem.

The seriousness of noise pollution’s impact on public health is supported by data collected by Rockwool from responses to a Freedom of Information Act (FOI) request by local governments. This research shows that between April 2008 and 2009, UK councils received 315,838 complaints about noise from private homes. This led to environmental health officers across the UK issuing 8,069 noise abatement notices, or legal warnings, under the Anti-Social Behaviour (Scotland) Act.

Westminster City Council received the most complaints per person in the UK, with 9,814 noise-related grievances. This equals 42.32 complaints for every 1,000 residents. Eight of the top ten councils with the highest number of complaints per 1,000 residents were located in London.

Annoyance

Sudden, unexpected noises are usually seen as more annoying than traffic noise of the same loudness. How much noise bothers a person is not much affected by age, gender, or other personal traits, but being afraid of the noise source or being more sensitive to noise strongly increases how annoying the noise feels. Sounds as quiet as 40 decibels (dB(A)) can cause complaints, and noise at 45 dB(A) or lower can disturb sleep.

Other factors that influence how annoying a sound is include beliefs about whether noise can be prevented and how important the noise source is. Being upset about the reason for the noise (which may not be related to the noise itself) also affects annoyance. How people interpret how annoying noise is and how it relates to health problems may be influenced by how well people get along at work and the stress caused by their jobs. There is not enough clear evidence about whether long-term noise or recent changes in noise levels have a bigger effect on annoyance.

About 35% to 40% of office workers find noise levels between 55 and 60 dB(A) very irritating. In Germany, the noise standard for tasks that are mentally demanding is 55 dB(A). However, if the noise is continuous, office workers are less able to tolerate noise levels below 55 dB(A).

Child physical development

The U.S. Environmental Protection Agency created a pamphlet in 1978 that showed a connection between low birthweight (defined by the World Health Organization as less than 2,500 grams or 88 ounces) and high sound levels. It also linked high sound levels to higher rates of birth defects in areas where pregnant women are exposed to loud noises, like typical airport environments. Specific birth defects mentioned include cleft lip, cleft palate, and spinal issues.

According to Lester W. Sontag of The Fels Research Institute (as presented in the same EPA study): "There is strong evidence that the environment influences the physical development, behavior, and function of animals, including humans, starting from conception and not just after birth. A fetus can hear sounds and react to them by moving or changing heart rate." The greatest effects of noise exposure occur between 15 and 60 days after conception, a time when major internal organs and the central nervous system are forming.

Later in pregnancy, noise exposure can cause blood vessels in the mother to narrow, reducing blood flow and limiting oxygen and nutrients to the fetus. Low birthweight and noise exposure were also linked to lower levels of certain hormones in the mother. These hormones are believed to affect fetal growth and are important for protein production. The difference in hormone levels between mothers in noisy and quiet areas became more noticeable as birth approached.

In a 2000 publication, a review of studies on birthweight and noise exposure noted that older studies suggested a small decrease in birthweight when women are exposed to more than 65 decibels of aircraft noise. However, a more recent study of 200 Taiwanese women that measured individual noise exposure found no significant link between noise and birthweight after accounting for other factors, such as social class and maternal weight gain during pregnancy.

When young children are regularly exposed to noise levels that interfere with speech, they may develop speech or reading difficulties because their ability to process sounds is affected. Children continue to develop speech perception abilities until they reach their teenage years. Evidence shows that children in noisier classrooms have more trouble understanding speech than those in quieter classrooms.

In a 1993 study by Cornell University, children exposed to noise in learning environments had difficulty distinguishing between words and experienced delays in cognitive development. Specifically, a learning condition called dysgraphia, which affects writing ability, is often linked to environmental stressors in classrooms.

High noise levels can also harm the physical health of young children. Children living in noisy homes often have heart rates that are, on average, 2 beats per minute higher than those of children in quieter homes.

Prevention

A hearing protection device (HPD) is a tool worn in or over the ears to help protect against loud noises that can harm hearing. HPDs lower, but do not completely stop, the amount of noise that reaches the ears. They also help reduce other problems caused by loud noises, such as ringing in the ears (tinnitus) and sensitivity to sound (hyperacusis). Keeping HPDs clean and well-maintained can help prevent infections in the outer ear. Many types of HPDs are available, including earmuffs, earplugs, electronic hearing protection devices, and semi-insert devices. A hearing protection fit-testing system can be used to measure how well a specific HPD blocks noise.

Earmuff-style HPDs are designed to cover the outer part of the ear, called the pinna. These devices usually have two ear cups connected by a headband. Earplug-style HPDs are placed inside the ear canal. Earplugs come in different forms. Some HPDs use both electronic parts and physical structures to reduce sound reaching the eardrum. Electronic HPDs are available in earmuff and custom earplug styles. These devices use microphones, circuits, and receivers to cancel noise. This process, called active noise reduction, works by creating sound waves that are opposite in direction to the noise, which theoretically cancels the noise. Canal caps are similar to earplugs, as they have a soft tip that fits into the opening of the ear canal.

OSHA requires workers to use hearing protection in noisy environments. However, HPDs alone (without proper fitting, training, and testing) do not greatly reduce the risk of hearing loss. For example, a study of more than 19,000 workers showed no major difference in the risk of noise-induced hearing loss between those who used HPDs and those who did not.

Regulations

Environmental noise rules often set the highest allowed outdoor noise level at 60 to 65 dB(A). Occupational safety groups suggest that workers should not be exposed to noise louder than 85 to 90 dB(A) for more than 40 hours each week. For every increase of 3 dB(A), the maximum time people can safely be exposed to noise is cut in half, such as 20 hours per week at 88 dB(A). Some guidelines use a reduction of 5 dB(A) instead of 3 dB(A), but health studies say these rules may not fully protect against hearing loss and other health issues. To help prevent hearing loss, programs like the Buy Quiet initiative encourage employers to buy quieter tools and equipment. Another example is the Safe-In-Sound Award, which honors organizations that successfully reduce hearing loss risks.

For indoor noise in homes, the U.S. Environmental Protection Agency (EPA) has not created specific limits for noise levels. Instead, the EPA provided suggested noise levels in its Model Community Noise Control Ordinance from 1975. For example, the recommended noise level inside homes is 45 dB(A) or lower.

Federal funding for controlling noise in homes is not available partly because it is hard to prove that certain sounds directly cause health problems. This is because noise effects are often linked to mental health and do not leave clear physical signs of harm. For example, hearing loss might be caused by aging or other factors, not just loud noise. However, state or local governments can regulate indoor noise if loud sounds from one home disturb nearby homes.