SoundEar noise warning devices cause a sustained reduction in ambient noise in adult critical care

Elevated sound levels in critical care are associated with sleep deprivation and an increased incidence of delirium. We aimed to determine whether a sound-activated visual noise display meter could cause a sustained reduction in sound levels overnight in an adult critical care unit. Sound levels were recorded overnight for eight days before and after the introduction of a visual noise display meter, with a further eight days recorded four months later after continued use of the visual noise display meter. Median ambient sound levels were significantly reduced from 57.4？dB by 3.9？dB, with a sustained reduction of 3.6？dB from baseline after four months of the device operating. Peak ambient sound levels had a small but significant reduction from 66.0？dB by 0.7？dB, with a sustained reduction of 0.8？dB after four months. Sound-activated visual noise display meters can be effective in providing a sustained reduction in ambient sound overnight in adult critical care units, which would appear to be driven by behavioural change