Miraculous Materials

The acoustics of facilities can be described as three functional areas: 1) ensuring sufficient sound isolation between spaces to enhance sleep and privacy, 2) reducing the intrusion of mechanical system noise, and 3) providing low sound reverberation with proper acoustics within spaces for speech intelligibility and comfort. The first two functions, sound isolation and mechanical system noise, are usually treated with material installations “behind the scenes” and so would not be visually apparent to someone in the space. The third function, proper room acoustics within a space, is accomplished using the appropriate surface finish materials and so should be integrated into the visual design for the space.

 

Many advances in medicine have come through the use of advanced materials. So too, modern building materials, only recently developed and now available, can be applied to the construction and maintenance of facilities to achieve the acoustical goals which support a healing environment.

 

Sound generated in one area or space must be adequately blocked from impacting the adjacent spaces. The sound of a patient room television must not awaken the patient in the next room. The conversations between the patient, the family and the caregivers must also be blocked to ensure privacy. Sound isolation is usually achieved through the use of heavy materials. An example of a good sound isolator is a thick concrete wall assembly. However, this wall type is not always practical or cost effective. Lightweight construction techniques using gypsum wall board (GWB) on steel studs are less costly but do not block sound as effectively. Modern materials are now available to improve the performance of GWB assemblies. Sound and vibration damping glues and sealants can be field applied between layers of wall board to increase sound isolation. If space is at a premium, with designers fighting for every inch, then high performance wall boards are available with the damping material layer built in at the factory for a thinner board with similar sound isolation results.

 

The noise from mechanical systems which provide essential heat, ventilation and air conditioning (HVAC) must never be allowed to interfere with the comfort and speech communication of the occupants in the spaces they serve. HVAC systems should be “felt and not heard”. Mechanical system design for quiet performance focuses on isolating the moving components of those systems, such as air handler fans and refrigeration compressors, from the occupied portions of the building. Placing these system components as far as possible from patients and caregivers is an important part of the initial design process. Another key technique is to install ductwork which is lined with fiberglass or another sound absorbent material to keep the delivered conditioned air quiet. Newly available ducts with an encapsulated lining, which will efficiently absorb sound but will not absorb pathogens, and are cleanable can provide the fan noise reduction needed. These acoustical treatments are even available for high efficiency particulate air (HEPA) filtration systems.

 

The acoustics of a room can greatly affect the comfort and speech communication of the occupants. Too much reverberation, or echoing of sound in the room, will make speech difficult to understand, particularly in larger spaces such as meeting rooms and lobbies. Excess reverberation can also induce a feeling of unease about the environment. Sound absorption materials on room surfaces can reduce reverberation, but large areas of absorption are needed to be effective. Fortunately, many attractive room finishes that efficiently absorb sound have been recently developed. All types of finish materials, including gypsum wall board, wood, plaster, metal and even glass can be obtained that provide excellent sound absorption. The appearance of these finishes is limited only by the designer’s imagination. These materials can put the finishing touches on a room design that sounds as great as it looks!

 

Are these advanced building materials, which can provide superior acoustics in healthcare facilities, a modern miracle? Perhaps, but they should now be in the tool box of every building designer and facilities manager. These materials will help to create a better facility with positive outcomes.

 

We welcome your thoughts on building acoustics, and your efforts to create an environment of healing.