The Economic Cost of Aircraft Noise

The Impact of Noise on Sleep 

This is the second in a series of articles on the economic impact of aircraft noise.  The previous article presented strong evidence that concluded: 

·         For residential areas and other similarly noise sensitive land uses, noise impact becomes significant in urban areas when the DNL exceeds 55 dB.  

·         In suburban areas where the population density is between 1250 and 5000 inhabitants per square mile, noise impact becomes significant when the DNL exceeds 50 dB. 

·         And in rural areas where the population density is less than 1250 inhabitants per square mile, noise impact becomes significant when the DNL exceeds 45 dB.  

The air into which second-hand noise is emitted and on which it travels is a shared public good.  It belongs to no one person or group, but to everyone.  People, businesses, and organizations, therefore, do not have unlimited rights to broadcast noise as they please.  This is especially true when it comes to interruptions to nighttime noise, and its impact on sleep.   

As a pilot who works primarily at night, and “attempts” to sleep in the day, I am very familiar with sleep cycle interruptions.  Noise from vacuums, routine maintenance, and loud neighbors are all occupational hazards of “daytime” sleeping in hotels.  It’s goes with the job, but that is a choice I made.  However, when the Airport Board decides to build an airport near someone else’s backyard, they are making a decision that will affect the sleep cycle of hundreds of other people.   

In 1983, the FAA requested NASA Langley Research Center to review the literature on “state of the art” sleep interference research¹.  Here is what NASA found:

NASA’s Conclusions Concerning Arousal from Sleep: 

1.     The threshold level of a noise which will cause arousal from sleep depends on sleep stage and the age of the subject, among other things.  Noise levels which can cause sleep disturbance cover a range of 35 to 70 decibels.

2.     In a normal 8-hour sleep night, more time is spent in lighter stages of sleep in the last half than in the first half.  This implies that airport use restrictions limiting early morning flight from 3 a.m. to 7 a.m. are particularly important.  

3.      Little or no physiological adaptation to sleep interference from noise occurs.

4.      Psychological annoyance from the effects of sleep interference from aircraft noise is probably more significant than the direct physiological consequences. 

While the NASA study concluded that sleep arousal could cause a psychological annoyance, later studies have shown it’s much worse than that. In 2004, the World Health Organization (WHO) also looked at the effects of noise on sleep².  It concluded that, “[sleep disturbances], when chronic, can have persistent and permanent effects on mental and physical health of exposed people. Effects include:  

·         Reduction of sleep efficiency,

·         Increased number of arousals,

·         Decrease of rapid eye movement (REM) sleep [possibly affecting long-term memory and spatial orientation]

·         Decrease of slow wave sleep (Non-REM sleep [possibly affecting the energy restoration quality of sleep]

·         Decrease of total sleep time 

The WHO has concluded that there is a clear link between environmental noise (including aircraft noise) and insomnia. Insomnia is an experience of inadequate or poor quality sleep characterized by one or more of the following: difficulty falling asleep, difficulty maintaining sleep, waking up too early in the morning, non-refreshing sleep.   

Risk groups for having their sleep disturbed by noise include: 

·         Children

·         Shift workers

·         Elderly people (their sleep is more shallow)

·         Patients at intensive care units

·         Low-birth weight infant units

·         Residents and disabled persons in nursing homes

·         Women during pregnancy and menopausal periods 

So, there is ample evidence to suggest that aircraft noise will impact the sleep patterns of Oldham County citizens.  However, there are many variables—proximity to the airport, age, gender, number of occurrences, and the time of night—that make it difficult to put a definitive price tag on the cost of sleep disturbance.  Difficult, but not impossible. 

Bottom Line:  The exposure to aircraft noise constitutes a major annoyance, especially when it comes to sleep disruption.  For people living around airports, sleep disturbance is a major problem which will lead to a diminished quality of life. 

Sources 

1. Federal Aviation Administration.  “Aviation Noise Effects”, Federal Aviation Administration, Washington D.C., Mar 85. www.nonoise.org/library/ane/ane.htm]

2. World Health Organization. “Report on Night Noise Guidelines,” 6-7 December, 2004.  Geneva, Switzerland, www.euro.who.int.