Earth Today | ‘Embrace natural sounds’
Published:Thursday | July 14, 2022 | 12:05 AM
FROM ELEVATED blood pressures to diabetes, there are many health impacts of noise associated with road traffic, railways, aircraft, wind turbines, and even leisure activities.
It has prompted the United Nations Environment Programme (UNEP), in its 2022 Frontiers report, Noise, Blazes and Mismatches: Emerging issues of environmental concern, to give attention to natural sounds.
“Night-time noise disturbs sleep and affects well-being the following day. Estimates suggest that in Europe, 22 million and 6.5 million people suffer from chronic noise annoyance and sleep disturbance, respectively. The elderly, pregnant woman and shift workers are among those at risk of noise-induced sleep disturbance. Noise-induced awakenings can trigger a range of physiological and psychological stress responses, because sleep is necessary for hormonal regulation and cardiovascular functioning,” said the report.
“There is (also) increasing evidence that traffic noise exposure is a risk factor for the development of cardiovascular and metabolic disorders, such as elevated blood pressure, arterial hypertension, coronary heart disease and diabetes. A conservative estimate indicates that long-term exposure to environmental noise contributes to 48,000 new cases of ischemic heart disease and causes 12,000 premature deaths annually in Europe,” added the chapter of the report on ‘Listening to cities: From noisy environments to positive soundscapes’.
It is against this background that the UNEP report recommends a refocus on natural sounds, which bring health benefits.
“A number of systematic reviews documented empirical research from both clinical physiological and subjective psychological studies of well-being in response to acoustic environments. The reviews reported the positive influence of natural sound and quietness on physical and mental health. The importance of natural sounds to general well-being may also be associated with evolutionary advantages. Natural sounds may signal a safe environment, reduce anxiety and offer mental recuperation, while a lack of natural sound may provoke a more alert and vigilant state, especially for those from vulnerable groups,” the report noted.
Meanwhile, even animal species are struggling under the weight of noise, particularly in cities, and even with their adaptability.
“Acoustic communication is vital for many animal species. Acoustic signals are used in a variety of communication contexts, including territory defence, warning of danger, locating or attracting a mate, and caring for offspring. While abrupt and unpredictable sounds may be perceived as a threat by animals, chronic acoustic disturbance such as traffic noise can interfere with acoustic communication and alter behaviours in a range of species,” reads the report.
“Abandoning noisy sites may seem the obvious response, but some animals adapt to noisy conditions instead, by altering their vocalisation timing or pattern to avoid having their signal masked … . Zebra finches and white-crowned sparrows slow down their tunes in response to city noise. These types of vocal modification have also been observed in frogs and insects, such as grasshoppers, living next to noisy highways,” it added.
Still, there are risks.
“These changes certainly help animals to be heard in noisy environments, but sometimes altered vocalisation patterns are considered less attractive by potential mates, therefore affecting reproductive success. And if species are not behaviourally flexible in producing or receiving signals, the inability to communicate may eliminate them from their habitats, with possible significant ecological implications,” the UNEP report revealed.
As part of efforts to create a healthy soundscape, the report proposes a number of green solutions, including the planting of vegetation in urban environments to “absorb acoustic energy, diffuse noise and reduce street amplification”.
“Tree belts, shrubs, green walls and green roofs have positive visual effects, in addition to helping amplify natural sounds by attracting urban wildlife,” the report said.