Exposure to high levels of noise causes hearing loss; stress and mental health disorders; sleep disturbances, and impairs cognitive functioning – Aruna Raghuram

In India’s crowded cities and towns, noise is omnipresent. Horns of vehicles blaring in thick traffic, sounds of machinery and drilling on construction sites, the rush of trains, trams, and aircraft, ambulance sirens, vendors using loudspeakers, religious celebrations and festivals… there’s no escaping noise pollution. Indoors in homes, sources of noise pollution include televisions, music systems, household appliances, and air-conditioning units, among others.

The World Health Organization (WHO) defines noise pollution as “unwanted or harmful sound that can adversely affect human health, environmental quality, and overall well-being”. It highlights that exposure to high levels of noise causes hearing impairment; stress and mental health disorders; sleep disturbances, cardiovascular and metabolic diseases and impairs cognitive functioning. In particular, noise pollution adversely impacts children, as their developing body organs and systems are more sensitive to environmental stressors. It impairs their cognitive abilities manifested as learning difficulties, memory problems, and poor attention spans; damages speech and language development; causes stress and anxiety; disrupts sleep and results in noise-induced hearing loss.

According to Dr. Meenu Singh, pediatrician and director of AIIMS (All India Institute of Medical Sciences), Rishikesh, prolonged exposure to high levels of noise damages children’s developing auditory canals and hearing capability. “Children’s auditory canals are smaller than of adults. If children are exposed to more than 70 decibels of sound for more than one hour per day it can lead to nerve damage and hearing loss. There is noise everywhere these days and families who live in crowded areas such as a marketplace and near railway lines are especially exposed to high noise levels,” says Dr. Singh who adds that noise pollution also prompts sleep disturbances and slows children’s language development and communication capabilities.

In the circumstance, Dr. Singh advises parents to minimise noise pollution exposure at home. “Restrict children’s mobile phone usage, especially playing video games. Moreover, parents should be role models. If they turn up the television to loud volume all the time, so will their children. Also, it is better for children to listen to music without earphones or earbuds. This way the sound gets dissipated and doesn’t come directly into the ear, limiting damage to the auditory canals,” she says. 

Hearing loss apart, constant exposure to noise adversely affects children’s concentration and attention spans and could lead to learning disorders. Dr. Kamala Mukunda, a Bengaluru-based educational psychologist and author, says that exposure to noise exceeding 60 decibels results in “children having trouble focusing and sustaining attention — two skills crucial for learning”. 

“If a child’s ability to focus and sustain attention i.e, her executive function is impaired, her ability to absorb new information, recall it, and bring the two together to create new knowledge is impaired. Consequently, her problem-solving capability which requires focus and sustained attention, is substantially reduced. Overall, this negatively impacts learning and, as a corollary, academic outcomes,” she says.

Dr. Mukunda also flags the psychological impact of noise pollution on children. “It can negatively affect children’s mental health. Especially if they experience lack of control over the production of noise, they will be stressed. When the noise, and therefore the stress, becomes chronic, it leads to anxiety and depression,” says Dr. Mukunda.

Several research studies have validated the damaging effect of noise pollution on children’s learning capabilities. Way back in 1975, a path-breaking study titled ‘The effect of elevated train noise on reading ability’ by Prof. Arline Bronzaft of the City University of New York, found a significant relationship between train noise and poor reading scores. Prof. Bronzaft found that students sitting on the noisy side of the school building adjacent to the railway tracks lagged in reading performance by as much as four months compared with children seated on the quiet side.

More recently, a 2022 study titled ‘Exposure to road traffic noise and cognitive development in schoolchildren in Barcelona, Spain: A population-based cohort study’ concluded that exposure to road traffic noise was associated with slower development of working memory, complex working memory, and reduced attention spans of schoolchildren. WHO recommends less than 35 decibels of noise in classrooms to ensure “good teaching and learning conditions” (see box).

5 ways to protect children from noise pollution

• Strictly regulate children’s time spent on electronic/digital devices such as television, mobile phones, laptops, music systems, etc.
• Ensure children don’t use earphones to listen to music for long periods of time.
• Campaign for ‘No horn/silent zones’ near schools.
• Encourage planting of trees as they act as a buffer absorbing excessive sound.
• If you live near an airport, highway or railway station, install rubber-insulated windows and doors at home to curb noise pollution.
• Pressurise the government to move industries to the outskirts of the city and restrict commercial activities in residential areas.