Delirium is a condition often found in Intensive Care Unit (ICU) patients. It describes a collection of symptoms such as disability to focus, disorientation and impaired cognition such as failing to recognize family. Research shows that patients with delirium are at higher risk of dying during or even after stay in the ICU. In the Clear Minds project from Philips that aims at reducing delirium, noise has been identified as a significant contributor to delirium. One way of reducing this noise is to motivate the staff to behave quieter. 

Delirium develops due to the great deal of mental and physical stress ICU patients experience, which can be caused by clinical and environmental factors. Examples of the latter are noise, light, temperature and air quality.
Within the Clear Minds project noise has been identified as a significant contributor to the development of delirium in ICU patients; hence reducing noise will reduce occurrence of delirium. Monitoring the soundscape of ICUs has enabled identification of different sources of noise and prediction of their contribution to delirium.
One source of noise is hospital staff (e.g. conversations, dropped objects, check-ups). The goal now is to motivate hospital staff to behave quieter, for example by making them aware of the noise contribution to delirium.  Next to not disturbing patients further, full acceptance of the final product by the hospital is important for its effectiveness, which is where designing for their subjective well-being comes into play.