One way of measuring how noise impacts on the community is to look at how many people are annoyed. The social survey found that almost half of Victorians (49 per cent) were disturbed or annoyed by environmental noise at some stage in the previous 12 months.

Sleep disturbance

Sleep disturbance from noise can have negative effects on physical and mental well-being, including increased blood pressure and heart rate, reduced concentration, fatigue and depressed mood.

One-quarter (24 per cent) of respondents to the social survey reported sleep disturbance from environmental noise at some stage in the preceding 12 months.

Day and night

The survey found that noise levels increased with human activity, urbanisation and industrialisation, generally following the pattern of motor vehicle use throughout the day and week. For example, the quietest period of the day was in the early hours of the morning from 2am to 4am. Noise levels increased during the morning and afternoon peak hours and gradually reduced through the evening and into the night.

Weekend mornings (6am to 12pm) were significantly quieter than weekday mornings. However, the few hours after midnight on weekends were louder than during the week.

Overall, nights, weekday early mornings and weekend mornings were the quietest times measured, reflecting less traffic. The social survey found that many noise sources caused greatest impact during these times, when the general ambient noise levels were lower.

The survey findings indicated that sleeping, resting and relaxing were important for the Victorian community, and that people were particularly concerned when noise disturbs these aspects of home life.

• LA90 1 hr – is commonly called the ‘background noise’, and refers to the lowest 10 per cent of the sound level over an hour of measurement
• dB — decibel, the unit of measure for sound or noise.