Photo: WikipediaThe crusade against leaf blowers may feel like it has been waged since the machines were invented, but studies may have found the reason why people hate the sound so much.
Landscapers often feel persecuted for simply trying to do their job with the best tools available, but it really isn’t their fault.
A study published in the Journal of Environmental and Toxicological Studies explored the characteristics of sound from gas-powered leaf blowers. Unlike lawnmowers or snow blowers, which have a similar dB(A) (A-weighted decibels), leaf blowers have been found to have low-frequency components that allow it to travel long distances and penetrate building walls.
This filtration of leaf blower noise through outer walls seems to be one of the reasons that makes it more irritable than other lawn care equipment.
“Our finding helps explain why so many people are complaining about the effects this noise is having on their health and quality of life,” said Jamie Banks of Quiet Communities and co-author of the study. “At these levels, operating even one gas leaf blower can affect an entire neighborhood.”
The study looked at the decibel level from the origin point to 800 feet away. While the leaf blowers were over 100 dB(A) at the source and decreased over distance, the low-frequency component persisted at a high level.
“From a community perspective, the sound ratings supplied by manufacturers do not take frequency into consideration,” said co-author Erica Walker, a recent graduate of the doctoral program at the Harvard T.H. Chan School of Public Health. “Our findings suggest that reporting more on a sound’s character may be a step in the right direction.”
Currently, dB(A) is the standard used to rate equipment noise and the metric most communities use when setting regulatory policies.
“We now know that this metric breaks down in instances where there is a significant low-frequency noise component,” Walker said.
The International Institute for Noise Control Engineering and the National Academy of Engineering have pointed out dB(A) is insufficient for describing the impact of sound that contains a strong low-frequency component.
Another element of the dislike for blower noise is the seemingly helpless nature of the victims.
A 2016 survey of 1,050 residents in various Boston area neighborhoods found that a majority felt they could not control the noise nor get away from it.
“That’s a very vulnerable place to be in,” Walker told The Washington Post. Another 79 percent believed that no one cared that it bothered them.
A growing number of people are becoming sensitive to low-frequency sound and the sound can cause serious health effects including vertigo, disturbed sleep, stress, hypertension, and heart rhythm disorders.
“When harsh noise hits, instead of reaching out to greet the world with open ears, we shrink back into shells, or try to; in truth, the ears can’t shut, nor like the eyes turn away,” wrote Kenneth Maue in the 1997 Right to Quiet newsletter. “Noise controls space like an occupying army, travels through walls, enters homes, molests bodies, violates privacy, stops thoughts, batters each of us into isolation.”
The World Health Organization recommends general daytime outdoor noise levels should be 55 dB(A) or less, but 45 db(A) is needed to meet sleep criteria. Healthful sleep can be impaired by noise even if the sleeper is not awakened.
Some may think that residents are simply being petty when they complain about leaf blower noise, but the Centers for Disease Control acknowledges leaf blowers as a source of harmful noise that can lead to permanent hearing loss.
“People need to recognize this type of noise is not just an annoyance; it is a public health problem,” Banks said. “We need to think about prevention.”
