You don’t have to spend a lot of time in hospitals to find out that patients are sick of the noise in their rooms. Press Ganey surveys, current literature on the subject, and the unsolicited comments we receive while measuring sound levels in hospitals all confirm that patients are most often displeased with the noise experienced in hospital patient rooms. Minimizing noise disturbance to patient rooms is an important aspect of acoustical design for healthcare facilities. But before we can reduce the noise levels, we need to know the sources of noise and understand the factors that influence its transmission.
Spend a few hours listening in a nursing unit and the typical noise sources are easy to discern: conversations between patients and visitors, patients and care givers, care givers and care givers; overhead pages; medical equipment alarms, pumps, and fans; televisions; carts rolling and visitors with hard soled shoes in the corridor; phones ringing at nurse stations and subsequent phone conversations; elevator bells and doors; and nurse call bells. The list goes on, but which of these many sources are most disturbing and how can design influence the levels heard by patients. In 2007, I presented a paper at the annual conference held by the Institute of Noise Control Engineering, Noise-Con 2007. This paper presented a study that we, along with BSA LifeStructures, conducted at Lakeland Regional Medical Center in St. Joseph, Michigan. The purpose of this study was to assess the acoustical environment in their existing nursing units and apply anything that might be learned to the design of their new hospital building.
Some new things were learned and much that was already known and often recommended by acoustical consultants was confirmed. The study showed that the use of acoustical ceiling tiles rather than gypsum board can reduce noise levels by 5 to 7 dBA. The data collected demonstrated the importance of not placing patient rooms along both sides of a corridor. Patient room doors typically remain open, allowing for easy transmission of noise between rooms located across the corridor from each other. New hospital designs almost always call for acoustical ceiling tiles, and patient rooms in new hospitals are rarely located along both sides of a corridor. However, many new hospital designs purposefully create a direct line of sight from the corridor to the patient and even from nurse stations to patients. Direct lines of sight may be beneficial in caring for patients but it allows for easier transfer of sound from the corridor to patients and from nurse stations to patients.
And how about patient room proximity to nurses’ stations? The study showed that patient rooms more distant from nurses’ stations are exposed to less noise. So what happens when a nursing unit has multiple nurses’ stations? Does this decentralization reduce the noise levels in patient rooms or increase it because you now have fewer rooms that are distant from a nurse station? This will be one of the design aspects that we will be reviewing when conducting the follow up study in the new hospital building. If you are interested in hearing more about this study, I’ll be presenting the results, including the results of the follow-up study in the new hospital building, at the ASHE Midwest Healthcare Engineering Conference this November in Indianapolis.