Alain Muzet — Page 2 | Search PubMed

PubMed2002

The Need for a Specific Noise Measurement for Population Exposed to Aircraft Noise during Night-time.

Most of subjective complaints about aircraft noise during night-time refers to sleep disruption. In order to protect populations who live around airports, it is of major importance to define levels of noise considered to be unacceptable during that particular time of the 24-hour period. In addition to an integrated indicator which describes the global noise exposure (Lden), the French authority on airport noise control (Autorite de Controle des Nuisances Sonores Aeroportuaires: ACNUSA) is considering the possibility of defining a maximum noise level [LAmax (1s)] that should not be exceeded at night (from 22.00 to 06.00) by any flying aircraft over residential areas. The main benefit of this single event indicator would be the identification of contravening vessels and application of possible penalty. It is believed that this type of sanction would help protecting sleep in highly noise-exposed areas.

Journal Article↗

PubMed2000

Sleep inertia.

Sleep inertia is a transitional state of lowered arousal occurring immediately after awakening from sleep and producing a temporary decrement in subsequent performance. Many factors are involved in the characteristics of sleep inertia. The duration of prior sleep can influence the severity of subsequent sleep inertia. Although most studies have focused on sleep inertia after short naps, its effects can be shown after a normal 8-h sleep period. One of the most critical factors is the sleep stage prior to awakening. Abrupt awakening during a slow wave sleep (SWS) episode produces more sleep inertia than awakening in stage 1 or 2, REM sleep being intermediate. Therefore, prior sleep deprivation usually enhances sleep inertia since it increases SWS. There is no direct evidence that sleep inertia exhibits a circadian rhythm. However, it seems that sleep inertia is more intense when awakening occurs near the trough of the core body temperature as compared to its circadian peak. A more controversial issue concerns the time course of sleep inertia. Depending on the studies, it can last from 1 min to 4 h. However, in the absence of major sleep deprivation, the duration of sleep inertia rarely exceeds 30 min. But all these results should be analysed as a function of type of task and dependent variables. Different cognitive functions are probably not sensitive to the same degree to sleep inertia and special attention should be provided to dependent variables as a result of the cognitive processes under review. Finally, sleep disorders represent risk factors which deserve new insight in treatment strategies to counteract the adverse effects of sleep inertia.

Journal Article↗