Assessing the exposure-response relationship of sleep disturbance and vibration in field and laboratory settings

Exposure to nocturnal freight train vibrations may impact sleep, but exposure-response relationships are lacking. The European project CargoVibes evaluated sleep disturbance both in the field and in the laboratory and provides unique data, as measures of response and exposure metrics are comparable. This paper therefore provides data on exposure-response relationships of vibration and sleep disturbance and compares the relationships evaluated in the laboratory and the field. Two field studies (one in Poland and one in the Netherlands) with 233 valid respondents in total, and three laboratory studies in Sweden with a total of 59 subjects over 350 person-nights were performed. The odds ratios (OR) of sleep disturbance were analyzed in relation to nighttime vibration exposure by ordinal logit regression, adjusting for moderating factors common for the studies. Outcome specific fractions were calculated for eleven sleep outcomes and supported comparability between the field and laboratory settings. Vibration exposure was significantly associated to sleep disturbance, OR = 3.51 (95% confidence interval 2.6–4.73) denoting a three and a half times increased odds of sleep disturbance with one unit increased 8 h nighttime log10 Root Mean Square vibration. The results suggest no significant difference between field and laboratory settings OR = 1.37 (0.59–3.19). However, odds of sleep disturbance were higher in the Netherlands as compared to Sweden, indicating unexplained differences between study populations or countries, possibly related to cultural and contextual differences and uncertainties in exposure assessments. Future studies should be carefully designed to record explanatory factors in the field and enhance ecological validity in the laboratory. Nevertheless, the presented combined data set provides a first set of exposure response relationships for vibration-induced sleep disturbance, which are useful when considering public health outcomes among exposed populations

Quantification of the effects of audible rattle and source type on the human response to environmental vibration

The present research quantifies the influence of source type and the presence of audible vibration-induced rattle on annoyance caused by vibration in residential environments. The sources of vibration considered are railway and the construction of a light rail system. Data were measured in the United Kingdom using a socio-vibration survey (N = 1281). These data are analyzed using ordinal logit models to produce exposure{response relationships describing community annoyance as a function of vibration exposure. The influence of source type and the presence of audible vibration-induced rattle on annoyance are investigated using dummy variable analysis, and quantified using odds-ratios and community tolerance levels (CTL). It is concluded that the sample population is more likely to express higher levels of annoyance if the vibration source is construction compared to railway, and if vibration-induced rattle is audible

Störande buller Kunskapsöversikt för kriteriedokumentation

Noise can affect a listener indirectly, even at high intensity levels more generally characterized by the risk for damage to the auditory system. This report focuses on those effects that are termed as annoyance. The annoyance concept adapted for this report encompasses not only reactions directly attributable to noise exposure, but even those reactions that may not be directly associated with the exposure, such as fatigue or irritability. Further, this report addresses how noise can affect performance, as well as how noise can affect various physiological measures of subjective response (e.g. fatigue and stress reactions). Chapter 2 is a presentation of critical physical properties of sound and how these properties can be evaluated. Chapter 3 deals with the physical characteristics of the sound and how these affect perceived annoyance. Chapter 4 is a presentation of how physical sound properties and hearing can affect speech perception. Chapter 5 reviews some of the nonacoustical aspects of annoyance. Three specific sound characters are focused upon and presented in separate chapters. Chapter 7 deals with low frequency noise, Chapter 8 deals with infrasound and Chapter 9 with ultrasound. In Chapter 6, specific problems in learning and performance that noise can produce in school environments are discussed.Buller kan föranleda problem på nivåer långt under de som kan ge upphov till hörselskador. De ljud som kan ge hörselskador kan också på andra sätt påverka dem som utsätts för det. Föreliggande dokument behandlar i huvudsak de av dessa effekter som kan ges den samlade beteckningen störning. I störningsbegreppet, som det används i denna rapport, ingår även andra reaktioner på bullret än direkta värderingar av bullret. I rapporten behandlas även sådana effekter som den bullerexponerade inte själv nödvändigtvis kopplar till bullret. Bullret kan t ex tänkas skapa trötthet eller irritabilitet utan att personen själv ser detta som en bullereffekt. I rapporten behandlas även andra uttryck för bullerstörning än de upplevelsemässiga. Bullret kan göra att arbetsuppgiften blir svårare att genomföra och det kan därför också försämra prestationen. I rapporten ingår även fysio-logiska manifestationer av den subjektiva och beteendemässiga störningen, t ex sömnighet och stressreaktioner. Kapitel 2 behandlar kritiska fysikaliska egenskaper hos ljudet och hur dessa kan mätas. Kapitel 3 tar upp hur de fysikaliska ljudegenskaperna bestämmer ljudets sensoriska kvaliteter och hur dessa påverkar störningsreaktionen. Kapitel 4 redovisar hur fysikaliska ljudegenskaper och hörselskada påverkar talinterferensen. Kapitel 5 behandlar de icke akustiska förhållandenas betydelse för störningsreaktionen. Tre ljudtyper har brutits ut och behandlas i särskilda kapitel. I kapitel 7 behandlas lågfrekvent buller, i kapitel 8 infraljud och i kapitel 9 ultraljud. Dessutom behandlas i kapitel 6 de speciella problem för inlärning och prestation som buller i skolmiljö kan skapa

Effects of nighttime low frequency noise on the cortisol response to awakening and subjective sleep quality

The effects of night-time exposure to traffic noise (TN) or low frequency noise (LFN) on the cortisol awakening response and subjective sleep quality were determined. Twelve male subjects slept for five consecutive nights in a noise-sleep laboratory. After one night of acclimatisation and one reference night, subjects were exposed to either TN (35dB LAeq, 50dB LAmax) or LFN (40dB LAeq) on alternating nights (with an additional reference night in between). Salivary free cortisol concentration was determined in saliva samples taken immediately at awakening and at three 15-minute intervals after awakening. The subjects completed questionnaires on mood and sleep quality. The awakening cortisol response on the reference nights showed a normal cortisol pattern. A significant interaction between night time exposure and time was found for the cortisol response upon awakening. The awakening cortisol response following exposure to LFN was attenuated at 30 minutes after awakening. Subjects took longer to fall asleep during exposure to LFN. Exposure to TN induced greater irritation. Cortisol levels at 30 minutes after awakening were related to 'activity' and 'pleasantness' in the morning after exposure to LFN. Cortisol levels 30 minutes after awakening were related to sleep quality after exposure to TN. This study thus showed that night time exposure to LFN may affect the cortisol response upon wake up and that lower cortisol levels after awakening were associated with subjective reports of lower sleep quality and mood