When answering Press Ganey, HCAP, and other surveys, patients regularly grade hospitals poorly on the question of noise in and near patient rooms. Analysis of historical data has shown noise levels in and near patient rooms steadily increasing over the past decades. Many hospitals have taken notice and are attempting to reduce noise levels, both in their existing facilities and when designing new facilities. In this blog post, I review some of the floor planning concepts that can be implemented during the early design phase to reduce noise in new facilities.
Direct line of sight is bad. Many nurses may not concur with me on this point, but with respect to noise control, it is undeniable. A direct line of sight from noise source to receiver means there is a direct path for sound to travel. The first place to apply this principle is in the layout of patient rooms. Layouts that allow line of sight from corridor to headboard should be avoided. Many of the intrusive noise sources of concern either originate in the corridor or are transmitted to patient rooms via the corridor. Unless there is a patient in isolation, patient room doors are rarely closed and a direct path for sound to travel will greatly limit the effectiveness of sound absorbing ceiling, wall, or floor surfaces. This direct line of sight frequently results from the desire to purposely create a direct line of sight or from the desire to provide for easy movement of patients and beds in and out of the room. Direct line of sight is less likely to occur if patient bathrooms are located toward the building interior rather than along the exterior wall. Even when bathrooms are located along the interior wall, they are sometime shaped such that the patient room entryway width expands as you enter the room, causing a direct line of sight to the patient. Regardless of the bathroom location, patient room entryways should be shaped so as to block the line of sight to headboards and as much of the patient bed as possible.
Direct line of sight from patient room to patient room is also a problem. This is rare in modern healthcare facility designs, but is common in older facilities where patient rooms were located along both sides of a corridor. Where patient rooms will be located along both sides of a corridor, patient room doorways must be staggered rather than located directly across the hallway from each other. If a person can stand in one room and look through the doorway into another patient room, then sound can easily travel from that room to the other. What is the most problematic sound that travels from patient room to patient room? - Television noise. Transmission of conversations from one patient room to another can also occur and is most frequently a problem when conversations are taking place with patients that are elderly and hard of hearing.
Certain adjacencies can also result in excessive noise intrusion into patient rooms. Elevator lobbies should be located distant from patient rooms. During past noise surveys, I have noticed that visitors will often lower their voices while walking in patient corridors, but will not lower them in elevator lobbies. Patients in rooms near elevator lobbies are exposed to the regular noise of the elevator chime and to the conversations of passengers.
Care should also be taken when locating exercise rooms and family gathering rooms. Where these spaces are located adjacent to patient rooms, walls may need to be upgraded to types with higher STC’s. Vertical adjacencies must also be considered. What is above the patient rooms? If patient rooms, bathrooms, and corridors are stacked then there is unlikely to be a problem with vertical transfer of noise. However, on occasion, designs locate other uses above patient rooms. A careful acoustical analysis should be performed if building mechanical services equipment rooms will be located above or adjacent to patient rooms. Other troublesome vertical adjacencies include MRI suites, certain types of operating rooms, and busy public spaces.
These are some of the space planning issues that impact the acoustical environment. In future blog posts, I will address the control of HVAC noise, use of sound absorbing finishes, attenuation at the source for the myriad noise sources that can intrude into patient rooms, and use of electronic sound masking systems.
Whether you’re located in Chicago or elsewhere, if you are designing a new hospital facility or need an acoustical expert to help assess noise in an existing facility, you can contact me at Soundscape Engineering (http://www.SoundscapeEngineering.com).