The WHO has published GUIDELINES FOR COMMUNITY NOISE which says:
For a good night’s sleep, the equivalent sound level should not exceed 30 dB(A) for continuousSome noise is inherent in nightclub presence - sirens, shouting, traffic, vehicle horns - and the more nightclubs, the more such noise. Our measurements of the noise at peak periods, like 2 AM, put the street noise levels in the mid-70s DB which mostly has a white noise character which attenuates naturally proportional to distance from the source. But the sleep-disturbing sounds reach into the brain's natural alarm function evolved long, long ago to alert our ancestors to danger.
background noise, and individual noise events exceeding 45 dB(A) should be avoided. In setting limits for single night-time noise exposures, the intermittent character of the noise has to be taken into account. This can be achieved, for example, by measuring the number of noise events, as well as the difference between the maximum sound level and the background sound level. Special attention should also be given to: noise sources in an environment with low background sound levels; combinations of noise and vibrations; and to noise sources with low-frequency components.
There is plenty of research on the physiological effects of various
noises, even relatively low dB noise, on sleep, such that
using sound amplitude (dB) as the sole measure is inadequate.
The information content of noise as well as the sound level is important for the person asleep. The alarm function of the sense of hearing may cause awakening even when the noise is very soft if the noise contains information important for the sleeping person. …… Frequent occurrence of arousals lead to a deformation of circadian rhythms. Deformation is revealed by a fragmented progression of sleep. Sympathetic tonus is increased as a result of the fragmentation of sleep during the night or of the multiple arousal occurrence. This leads to impaired sleep quality and to decreased performance capacity, drowsiness and tiredness during the day. …… Sudden, unexpected noise events set off a series of stress reactions with an initial startle reflex, followed by an orienting reaction directed towards locating and validating the sensory stimulus. This reaction habituates relatively fast. The sequence of the stress reactions under concern is genetically programmed and provide biologically vital protection strategies without adverse effects on health as long as they occur seldom ….. Neuro-endocrine effects during sleep: The following is focussed on why the sleeping human organism responds to low noise levels with considerable cortisol increases . Our ear is on the alert day and night serving as our most important sensory warning system. This is a reason why environmental sounds are percepted and processed whether a person is awake or asleep. In sound processing, specific subcortical areas of the CNS play an essential part in increases of cortisol concentration during sleep at low sound levels. [Ising, Berliner Zentrum Public Health]The letters from residents complaining of the noise interruptions of sleep all focus on the music, which does not diminish by habituation. Sirens and horns are bad enough because their function is to trigger that brain alarm through auto windows. But some music has the same effect, particularly the brand of music typically played at high volume (even over 100 dB) because research finds that it actually increases drinking. A French experiment found that loud music increases the speed of drinking by 20%. One clue is the frequent use of an alarm clock-radio tuned to a music radio station.
Research has shown that sensitivity to noise cannot be easily
defined and reduced to a single variable. [see Soames, Job R F, Noise sensitivity as a factor
human reaction to noise, Noise Health 1999;1:57-68] The Palladium
residents who describe their reaction to the late-night music are
oblviously sensitive to that combination of place, time, and noise
source. The wide variability
of sensitivity argues for a rule that controls the noise impinging on
the residence rather than putting the burden on resident to defend
against whatever noise assault they find thenselves under.
The [British] Chartered Institute of Environmental Health noted that "The commonest type of offending noise is not pneumatic drills, cars or aircraft, but music." Although that finding was used in a Campaign for Freedom from Piped Music, the pertinent phemonenon is the same as night club music in residential neighborhoods - unwelcome music to residents "trapped, with no chance of escape from someone else's choice of music." [Simon Frith, Music and everyday life, Critical Quarterly, Volume 44, Issue 1, pages 35–48, April 2002] Unwelcome music, even at low volume as is background music in airports, triggers an adverse reaction. It is certainly within the realm of possibility that the resident letter writers are only the worst affected of a large population of residents who are disturbed in sleep by such music but do not cennect their disturbance with low level musical sounds. The operating criterion for residents should be that they be free from unwelcome music in the sleeping hours. If a busker can be banned, so should a nightclub music maker.
Research continues. Ising and Kruppa (2004) reviewed the
state of the art.
Previously, extraaural noise effects were mostly assessed using a paradigm in which the sound level played the major role. On the basis of this paradigm the relatively low sound level of environmental noise was not considered to be a potential danger to health. In contrast to this numerous empirical results have shown longterm noise-induced health risks. Therefore a radical change of attitude - a change of paradigm - is necessary. For an immediate triggering of protective reactions (fight/flight or defeat reactions) the information conveyed by noise is very often more relevant than the sound level. It was shown recently that the first and fastest signal detection is mediated by a subcortical area - the amygdala. For this reason even during sleep the noise from aeroplanes or heavy goods vehicles may be categorised as danger signals and induce the release of stress hormones. In accordance with the noise stress hypothesis chronic stress hormone dysregulations as well as increases of established endogenous risk factors of ischaemic heart diseases have been observed under long-term environmental noise exposure. Therefore, an increased risk of myocardial infarction is to be expected. The results of individual studies on this subject in most cases do not reach statistical significance. However, according to the Environmental Expert Council, these studies show a consistent trend towards an increased cardiovascular risk if the daytime immission level exceeds 65 dB(A). [Ising H, Kruppa B. Health effects caused by noise : Evidence in the literature from the past 25 years. Noise Health [serial online] 2004;6:5-13. Available from: http://www.noiseandhealth.org/text.asp?2004/6/22/5/31678]Some added evidence comes from the war on terror, it is absolutely clear that music plays an important role in the interrogation of detainees in the war on terror. [Suzanne Cusick, Music as a weapon / Music as torture 2006] Although loud bar music heard at a distance does not reach the level of torture (even to the bar patrons who seem to demand such music), that is
the state’s interrogators share with many civilian musicians, composers and scholars the notion that listening to music can dissolve subjectivity, releasing a person into a paradoxical condition that is both highly embodied and almost disembodied in the intensity with which one forgets important elements of one’s identity, and loses track of time’s passing,the fact of music's ability to disturb individuals suggests that some residents could be distinctly affected, even unknowingly. The letter writers attest to some damage to some people, a sufficient condition for eliminating the source of damage, a source that has no useful public purpose that merits continuance.