[Street noise and sleep: whole night somnopolygraphic, psychometric and psychophysiologic studies in comparison with...

In 3 sleep-laboratory studies the effects of nocturnal traffic noise on the sleep of young (1st study: mean age 25 years, n = 10) and elderly (2nd study: mean age 62 years, n = 10) healthy subjects as well as adaptation phenomena (3rd study: one week in young volunteers, n = 10) were investigated. Objective sleep quality was evaluated for baseline- and traffic noise-conditions by means of somnopolygraphic all-night recordings between 22:30 ("lights out") and 6:00 ("buzzer") in the sleep-laboratory. In the morning sleep- and awakening quality were measured by a self-rating scale and psychometric and psychophysiological tests. Traffic noise, presented by a loudspeaker throughout the night with an intensity of 68 to 83 dB (A) (L eq = 75.6 dB [A]), caused a lengthening of sleep latency and intermittent wakefulness as well as a reduction of total sleep time and sleep efficiency as compared to baseline. Concerning sleep architecture, traffic noise led to an increase of light sleep, while deep sleep and, more pronounced, REM sleep were shortened. Although we found these changes in both generations, they reached the level of significance in young subjects only. The objective results were reflected in a significant deterioration of subjective sleep- and awakening quality after traffic noise. Objective awakening quality was unaffected . In the course of a one-week nocturnal traffic noise, we observed an increase of S 4 and a decrease of S 3. The last 3 nights revealed a significant improvement in subjective sleep quality, suggesting adaptive phenomena.(ABSTRACT TRUNCATED AT 250 WORDS)