Effect of noise tolerance on non-restorative sleep: a population-based study in Hong Kong.

OBJECTIVE: The aim of this study was to assess the impact of auditory noise tolerance on non-restorative sleep using an objective audiometric test in a representative sample.

DESIGN: A total of 202 Chinese individuals aged 15 years and above were recruited from a population-based household survey. Their non-restorative sleep was assessed by a single item, the degree of feeling refreshed on waking up, on a 0-10 scale, while noise tolerance was measured by the most comfortable level expressed in A-weighted decibels.

RESULTS: The 202 individuals (106 women) had a mean degree of feeling refreshed on waking up of 6.5 on the 0-10 scale and a mean maximum comfortable sound level of 69.2 dB. A multivariable analysis showed that a 1 dB increase in noise tolerance was associated with a 0.1-unit increase in the degree of feeling refreshed after adjusting for age, education, marital status, occupation, exercise, smoking, alcohol consumption, household noise level, stress, anxiety and depression. Moreover, housewives, non-smokers and individuals who were less anxious or stressed felt significantly more refreshed on waking up.

CONCLUSION: People with higher levels of noise tolerance experienced more refreshing sleep. Additional clinical consideration of enhancing noise tolerance in patients with sleep complaints is needed.