Associations of Various Nighttime Noise Exposure Indicators with Objective Sleep Efficiency and Self-Reported Sleep...

Area of Science:

• Environmental Health
• Sleep Science
• Acoustics

Background:

• Nighttime noise exposure is a common environmental stressor.
• The specific timing and characteristics of noise most detrimental to sleep quality remain unclear.
• Real-world data on noise effects on sleep are needed.

Purpose of the Study:

• To investigate the impact of different nighttime noise exposure windows on objective and subjective sleep quality.
• To identify critical noise characteristics and timing for adverse sleep outcomes.
• To inform public health guidelines on managing nighttime noise pollution.

Main Methods:

• A field study involving 105 volunteers over seven days.
• Concurrent objective sleep monitoring using wrist actimetry and outdoor noise measurements.
• Analysis of noise exposure (L_eq,1h) during specific nighttime windows and its correlation with sleep latency, efficiency, and self-reported sleepiness.

Main Results:

• Increased noise in the first hour after bedtime prolonged sleep latency by 5.6 min per 10 dB(A).
• Noise during the last three hours of sleep reduced sleep efficiency by 2%-3% per 10 dB(A).
• Noise in the final hour before waking significantly increased self-reported sleepiness (0.31 units per 10 dB(A)).

Conclusions:

• Noise exposure at the beginning and end of the sleep period is most critical for sleep quality.
• Matching noise exposure time windows to individual sleep-wake patterns improves the estimation of noise's detrimental effects.
• Outdoor noise levels were as impactful as estimated indoor levels, suggesting the importance of external noise sources.