nora Study Examines In-Room Impact Noise Reduction of Varying Flooring Materials
Several factors contribute to a space’s acoustic environment, from the drone of air conditioning, to the ceiling tile, to a cart rolling across the floor. However, there is little research that explores how flooring can help reduce “in-room” impact noise. Comprehensive standards and design guidelines that address in-room impact sound can support end users, consultants, designers and specifiers with tools to help improve the acoustic environment in any space, from hospitals, to hotel lobbies and offices, to classrooms. nora sought to expand current third-party research and support the development of a new testing standard for floor impacts within a room.
Acoustics in Healthcare and Education
In the healthcare environment, increased noise levels can result in higher rates of sleep disturbance and extended length of hospital stays, among other negative health effects. However, for hospitals across the U.S., “Quietness of Hospital Environment” has consistently been the lowest or second lowest scoring category of the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) ten evaluation categories for the last several years.
A basic requirement in the learning environment is everyone’s ability to hear and be heard clearly, as noise distracts from focus and lowers speech intelligibility, which can have a significant impact on comprehension. While research links acoustics to student learning and achievement, the Acoustical Society of America estimates that many classrooms have a speech intelligibility rating of 75% or less, where a rating of 95% is recommended.
This study investigated in-room sound reduction provided by 10 flooring types, using various impactors as noise sources including small and large impactors, different wheel types and a book dropping. The testing methodologies were conducted on a large concrete slab, to which each flooring type was adhered according to the manufacturers’ recommendations.
The results demonstrate that with a large, heavy impactor, only the 4 mm premium rubber acoustic flooring and carpet provide a significant reduction in sound level. Further, regardless of drop height, the 4 mm premium rubber acoustic flooring provided more sound level reduction than carpet with a smaller impactor.
While carpet provided the best attenuation for the rolling noise source, it also proved the disadvantage of increased rolling resistance. Premium rubber acoustic flooring provided the next highest amount of noise reduction at 8 dBA.
Evidence of Impact
Findings from this study provide evidence that flooring can greatly affect in-room impact noise. Further, this research provides a repeatable testing methodology to compare the amount of in-room impact sound reduction provided by various flooring types.
The full study can be downloaded here.
For more information, visit www.nora.com.