Noise and sleep on board vessels in the Royal Norwegian Navy

Abstract

Previous research indicates that exposure to noise during sleep can cause sleep disturbance. Seamen on board vessels are frequently exposed to noise also during sleep periods, and studies have reported sleep disturbance in this occupational group. However, studies of noise and sleep in maritime settings are few. This study's aim was to examine the associations between noise exposure during sleep, and sleep variables derived from actigraphy among seamen on board vessels in the Royal Norwegian Navy (RNoN). Data were collected on board 21 RNoN vessels, where navy seamen participated by wearing an actiwatch (actigraph), and by completing a questionnaire comprising information on gender, age, coffee drinking, nicotine use, use of medication, and workload. Noise dose meters were used to assess noise exposure inside the seamen's cabin during sleep. Eighty-three sleep periods from 68 seamen were included in the statistical analysis. Linear mixed-effects models were used to examine the association between noise exposure and the sleep variables percentage mobility during sleep and sleep efficiency, respectively. Noise exposure variables, coffee drinking status, nicotine use status, and sleeping hours explained 24.9% of the total variance in percentage mobility during sleep, and noise exposure variables explained 12.0% of the total variance in sleep efficiency. Equivalent noise level and number of noise events per hour were both associated with increased percentage mobility during sleep, and the number of noise events was associated with decreased sleep efficiency.

Physical influences on seafarers are different during their voyage episodes of port stay, river passage and sea passage: A maritime field study

“…The search for ever faster and more economical ships is difficult to reconcile with the demand for a quiet, low-vibration and well air-conditioned working and living environment on board. Physical stress, such as noise, vibration and heat, sometimes elicits considerable strain on the shipboard crew [1][2][3]. Several previous maritime studies have shown that these variables are the main physical influences that can affect the well-being of seafarers [1,2].…”

The effect of hardiness on symptoms of insomnia during a naval mission

“…Natvik et al [20] found that hardiness was negatively associated with insomnia symptoms and sleepiness in both samples of two and three shifts. although these samples are from different job context and not operative professions, the results are noteworthy, given that the crew of modern naval vessels also work in shifts [2]. Thus, we hypothesize a main effect of hardiness, where higher levels of hardiness are associated with less insomnia symptoms before, during and towards the end of the mission.…”

“…lack of sleep or a disturbed sleep cycle is a distinct stressor [4]. The working conditions of a modern naval ship may entail long periods without sleep [2,7]. The sleep environment on board may feature several physical stimuli, which affect sleep quality negatively.…”

“…Similar to civilian vessels, a modern naval vessel is comprised of sailors, officers and enlisted personnel working and living in a complex system of interacting stressors [2,6]. These stressors affect the operational capability of the crew.…”

“…This demanding situation has several consequences. One of them is reduced sleep quality and quantity [2]. Sleep has an important function in performance, cognition and motor functions [3].…”