Project

Discipline

night-time transportation noise; noise & health; arousal probability; awakening; sleep-related noise sensitivity

Lead
Nächtlicher Verkehrslärm (Strassen-, Schienen- und Flugverkehrslärm) kann zu lärmbezogenen Aktivierungs- und Aufwachreaktionen während des Schlafs führen. Da ein gestörter Nachtschlaf die körperliche sowie geistige Gesundheit und Leistungsfähigkeit beeinträchtigt, ist ein Hauptziel der Studie, folgende Einflussfaktoren auf die nächtlichen Lärmwirkungen zu untersuchen: Lärmcharakteristika (wie Höhe und Anstieg des Schallpegels), individuelle Faktoren (wie Lärmsensitivität und genetische Prädisposition) sowie Schlafcharakteristika (wie Schlaftiefe).
Lay summary
Inhalt und Ziele des Forschungsprojekts Das Hauptziel des vorliegenden Projekts ist die Charakterisierung und Quantifizierung von transient vorkommender rhythmischer Hirnaktivität und deren Rolle bei der lärmbezogenen Aktivierung im Schlaf. Zum anderen soll der Einsatz computergestützter automatischer Algorithmen für die Auswertung der Hirnstrom-Signale (EEG; Elektroenzephalografie) bezüglich Aktivierungs- und Aufwachreaktionen entwickelt, getestet und validiert werden. Wissenschaftlicher und gesellschaftlicher Kontext des Forschungsprojekts Das Projekt leistet einen Beitrag für ein verbessertes Verständnis der neurophysiologischen Lärmwirkungen während des  Schlafs. Langfristig könnte dies zu einer Verbesserung des nächtlichen Lärmschutzes führen und so lärmbezogene Schlafstörungen reduzieren.

Direct link to Lay Summary

Last update: 28.01.2017

Number	Title	Start	Funding scheme

Background: Environmental noise is one of the most common complaints for disturbed sleep. Night-time transportation noise disturbs sleep and it impairs recuperative sleep functions by reducing sleep time, causing awakenings, sleep-stage changes or cortical arousals. Aims: The maximum sound pressure level of a distinct noise event is a common acoustical factor in estimating exposure-response functions whereas other noise exposure patterns such as the temporal distribution of the sound pressure level might be better suited to estimate noise-induced adverse effects. There is evidence from basic sleep research that during sleep spindle presence arousability from sleep by single tones is reduced indicating a possible physiological marker of sleep-related noise sensitivity. Additionally, the role of brain rhythms that share common features with classic activation complexes during sleep needs to be elucidated. Finally, the moderating effect of genetic predispositions such as a polymorphism in the clock gene PER3 that predispose the sleeper to noise-induced sleep disruptions needs to be considered. The role of acoustical metrics and possible moderating and mediating variables and their short-term effects on cognitive functioning and vigilance were investigated in multi-methodological laboratory experiment. Methods: 44 participants of the two age groups (19-35 and 50-75 years) spent six scheduled night-time sleep episodes and five scheduled wake episodes on consecutive days in our highly controlled laboratory facilities. A within-subject, crossover design was employed where every participant was exposed to four different noise scenarios that were flanked by a noise-free baseline and a recovery night. The noise scenarios differed with respect to noise source (railway noise and different road traffic situations) and short-term exposure variation over time [Intermittency Ratio (IR) low, medium or high] but had a constant hourly Leq of 45 dB(A) at the sleeper’s ear. Polysomnographic signals (electroencephalography, electrooculography, electromyography, and electrocardiography) were recorded continuously during the night and during day-time vigilance tasks. Cognitive functioning was assessed four times a day utilizing validated instruments to evaluate vigilance, memory and working memory performance. Relevance: The identification of potentially vulnerable subgroups on the basis of a physiological marker for sleep-related noise sensitivity or a sleep-related genetic predisposition is relevant given the fact that a significant part of the Swiss population is exposed to problematic night-time noise levels.