Despite the findings on helicopter noise and These findings certainly suggest that helicopter flight should be regulated in response to the exceptional levels of noise they produce. This would place perceived helicopter noise at around 97 dB, or a whopping 30 dB’s over the generally accepted noise level of residential areas. The helicopter’s unique sound, created by blade vortex interaction, causes people to rate its sound level as much as 10 dB’s higher than it actually registers, doubling the noise impact. Eight different studies have found that the annoyance created by a helicopter does not correlate with the decibels it registers. Helicopters rank especially high in causing undesirable noise. In addition, people get really pissed off with an LAPD Bell 206 hovering over their barbeque! Environmental Protection Agency in 1979, noise can affect mental health and has been implicated in producing stress-related health effects such as strokes, ulcers, heart disease, and high blood pressure. According to the Noise Effects Handbook, published by the U.S. In addition to hearing loss at the extreme and a loss of concentration at the least, noise exposure causes behavioral changes and irritation, according to the World Health organization. Noise is the great leveler and while noise is born as a noun, it quickly morphs into an adjective, certainly in our context. Local governments cannot prefer the sound of Brahms to the B-52’s, only when, where, and at what volume. This is the basis for local and municipal governments noise control ordinances.
HAI notes that to meet the generally acceptable criterion of 65 dB, helicopters should fly at altitudes no less than 1,000 feet.Įxcessive and annoying noise goes beyond aesthetics and may be detrimental to public health. That effectively reduces by half the impact of the resultant noise. Here, we will review some interesting aspects of noise related to the flight.Īccording to the Helicopter Association International (HAI), the difference in sound level of a helicopter flying at 500 feet and at 1,000 feet is nine decibels - dropping from 87 dB to 78 dB.
Last week we discussed an increase in the use of helicopters in Los Angeles correlated with nuisance complaints regarding loosely regulated helicopter flights.