Article,
Effects of low levels of road traffic noise during the night: a laboratory study on number of events, maximum noise levels and noise sensitivity
Journal of Sound and Vibration, (1995)
Abstract
The objective of the laboratory study presented here was to elucidate
the importance of the number of noise events of a relatively low
maximum noise level for sleep disturbance effects (body movements,
subjective sleep quality, mood and performance). Twelve test persons
slept eight nights under home-like laboratory settings. During four
of these nights, each test person was exposed to 16, 32, 64 and 128
noise events respectively from recorded road traffic noise at a maximum
noise level of 45 dB(A). All test persons (aged 20–42 years) considered
themselves rather or very sensitive towards noise. The results show
a significant decrease in subjective sleep quality at 32 noise events
per night. At 64 noise events, 50% of the test persons experienced
difficulties in falling asleep and, as compared with quiet nights,
the time required to fall asleep was on average 12 minutes longer.
The occurrence of body movements was significantly related to the
reported number of awakenings, and the number of body movements was
three times higher during the noisy periods of the night as compared
with the quiet periods, indicating acute noise effects. The results
of a vigilance test indicate that noise during the night might prolong
the time needed to solve the test. Finally, and regardless of number
of noise events, a significant increase in tiredness during the day
was found after nights with noise exposure. In the paper comparisons
are also made with earlier experiments using maximum noise levels
of 50 and 60 dB(A).
