Sound levels in single vs. double bed ICU rooms: A high-resolution sound study.

OBJECTIVES

High sound levels in intensive care units lead to increased rate of delirium and sleep disturbances in patients but also decreased work performance of healthcare providers. It is unclear how much impact different architectural settings have. The study aimed to determine whether sound levels in ICUs differ between single- and double-bed rooms.

METHODS

This prospective observational study collected sound level data in three architecturally identical ICUs at the Medical University of Graz. Recordings were made every 5 s, then aggregated into 1-minute and subsequently hourly intervals. For each hour, mean (LAeq), minimum (LAmin), and maximum (LAmax) sound pressure levels and standard deviations were calculated. Hourly sound levels between single- and double-bed rooms were compared by independent-samples t-tests. Secondary analyses examined day-night differences. All values were compared against WHO guideline thresholds.

RESULTS

A total of 188 ICU patients were included, generating over 11 million sound data points. Contrary to expectations,single-bed rooms exhibited significantly higher LAeq(51.85 dBA vs. 50.29 dBA;p = 0.026),higher LAmin(41.22 dBA vs. 35.34 dBA;p < 0.001), andlower LAmaxcompared to double-bed rooms (67.80 dBA vs. 70.89 dBA;p = 0.023). Across all room types, sound levels were significantly higher during daytime for all parameters. None of the hourly values met WHO sound thresholds.

CONCLUSIONS

Single-bed ICU rooms showed higher average and baseline sound exposure than double-bed rooms, challenging assumptions about acoustic advantages of single occupancy. Sound levels always remained above international recommendations.

IMPLICATIONS FOR CLINICAL PRACTICE: These findings highlight the need for multimodal strategies to reduce ICU sound, including staff awareness, alarm management, and architectural considerations. Structural design alone is insufficient; targeted behavioural and environmental interventions are essential to create quieter ICU environments.