The worst noise comes from the (L.A. Sheriff’s Department) choppers when they circle over a problem near my home. I know it is necessary, but the vibrations do cause damage, both to my nerves and things that fall from shelves and walls. I know they are capable of hovering, but their policy is to circle at very low altitudes. – A Compton resident*

INFOGRAPHIC: Click here to launch "Helicopter Noise Reduction by Altitude" by Brian Frank

This is part four of a series about helicopter noise in Los Angeles. Read part one and part two and part three.

Richard Root once counted 50 helicopters flying overhead in one day.

That was a record high, said Root, a Torrance resident who founded HelicopterNoise.com, but the average is still around 30 a day with a decibel reading between 65 and 70.

Unlike many others who have tried, Root has had some success in getting helicopter noise regulations implemented. It took a couple years for him to convince the Coast Guard to move its normal flight path a few miles west over the Pacific Ocean, but they finally complied. And the Torrance City Council agreed that helicopters should fly above 1,500 feet instead of 600, which was the previous altitude limit.

Root is not alone in his desire to curb the chopper noise. A survey of 60 Los Angeles residents in May found that 60 percent believed new regulations should apply to police helicopters. Nearly 90 percent said new rules should apply to the media. (To see the full survey, click here).

As for Root, even his case cannot be called a complete victory - at least not yet. The FAA still has to weigh in, and they won't do that until they have completed a pair of studies - one looking into sound, the other, safety.

So is helicopter noise an annoyance that residents should endure or is it a health issue that we should take seriously? Or are they one in the same?

According to the World Health Organization: Noise exposure can cause behavioral changes, problems with self-confidence and irritation.

According to the U.S. Environmental Protection Agency: Noise can lead to stress-related health effects such as strokes, ulcers, heart disease and high blood pressure.

A sound level of 75 decibels will be so annoying that it is likely to be the most important issue in a community, according to the EPA’s noise handbook.

An AStar helicopter, intermediate sized craft used by the LAPD, produces 87 decibels at 500 feet. According to several studies, people register this noise nearly 10 decibels higher, at about 97 decibels. A jackhammer is 100 decibels.

The LAPD usually flies between 500 and 700 feet.

There is no reason to have a helicopter hovering over my house several nights per week. I've called the non-emergency police number numerous times over the past four years since I've moved to Silverlake and am told various reasons for the helicopters - from fire or rescue training to chasing "bad guys" with guns or graffiti artists. I believe most of the worst helicopter noise is caused by the police. Do they honestly ever catch anybody with a helicopter? It's such a ridiculous amount of noise. In fact, in the time it has taken me to write this, I have heard four separate helicopters. And, I'm a fast typist. It sucks. – A Silverlake resident*

*Starred comments taken from a survey taken in May 2011, distributed to members of LeimertParkBeat.com, EchoParkOnline.com and SanPedroNewsPilot.com. It was also sent out on Twitter specifically through @Venice311, @CoCoSouthLA and @HubCityLivin. At the time the story was written 57 surveys were completed. To see the survey, click here.
To take a survey about helicopter noise, click here.