Efficacy and mode of action of a noise-sensor light alarm to decrease noise in the pediatric intensive care unit: a prospective, randomized study.

OBJECTIVES: To determine whether a sound-activated light-alarm device could reduce the noise in the central area of our pediatric intensive care unit and to determine whether this reduction was significant enough to decrease the noise that could be perceived by a patient located in a nearby room. The secondary objective was to determine the mode of action of the device. DESIGN: In a 16-bed pediatric and neonatal intensive care unit, a large and clearly noticeable sound-activated light device was set in the noisiest part of the central area of our unit, and noise measurements were made in the central area and in a nearby room. In a prospective, quasi-experimental design, sound levels were compared across three different situations--no device present, device present and turned on, and device present but turned off--and noise level measurements were made over a total of 18 days. PATIENTS/SUBJECTS: None. INTERVENTIONS: Setting a sound-activated light device on or off. RESULTS: When the device was present, the noise was about 2 dB lower in the central area and in a nearby room, but there was no difference in noise level with the device turned on vs. turned off. CONCLUSION: The noise decrease in the central area was of limited importance but was translated in a nearby room. The sound-activated light device did not directly decrease noise when turned on, but repetition of the visual signal throughout the day raised staff awareness of noise levels over time.