Noise within a space can be unpleasant, and in certain applications, it can be detrimental. Unwanted noise can hinder teaching and learning in schools, negatively impact productivity in offices and worsen patient and staff outcomes in hospitals.
The walls, floor and ceiling of a space affect the acoustic properties of a room. Within the flooring sector specifically, different floor coverings have different effects on the sound within a space. Softer materials such as textile composite flooring and carpeting can absorb significantly more sound than harder materials like resilient flooring, vinyl and rubber. Flooring manufacturers have continued to tweak their products so that less sound is reflected and transmitted, which means that a quieter environment can be achieved if the right flooring system is specified.
Two tests, namely structure-borne noise reduction and airborne noise reduction, are typically used by laboratories to measure the amount of sound transmitted within a space. Other tests that determine the acoustics of a construction material include reverberation time and speech intelligibility. Reverberations refer to the continuing effects of sound (like echoes), or speech recognition if there is a shorter reverberation time within a space. Speech intelligibility refers to the degree to which speech can be understood. If the background noise equals speaking volume, then a person’s ability to recognise speech will be very low. According to a study entitled Noise in Hospitals: Effects and Cures, a person must speak 12 decibels (dB) louder than the ambient noise to achieve 95% speech recognition. Every 10dB increase seems twice as loud to the human ear.
As a designer or specifier, you need to specify a flooring product that can support the activities and functions of a space. While a floor can make a huge difference to the acoustics within a building, other noise-reduction strategies also need to be considered to obtain a holistic view of how optimal sound quality can be achieved. A floor can contribute to acoustical management, but the ceiling, walls and other sound-masking technology also have to be carefully weighed and analysed.
While many professionals in the built environment have already mastered the environmental aspect of achieving “green” buildings, many green accreditation institutions are now focusing on the well-being of the occupants of a building along with sustainable and environmental responsibility. The indoor environmental quality of a building (IEQ) relates to the air quality, lighting levels and noise levels within a structure as these elements have a significant effect on the occupants and can have a far-reaching impact on the health and productivity of staff, and essentially the bottom line of a business. The Green Building Council of South Africa’s Green Star Rating Tool aims to “recognise buildings that are designed to maintain internal noise levels at an appropriate level” by awarding up to two Green Star points for such projects.
There are different sound ratings for various applications, such as health care facilities, multiple-story dwellings, hotels, apartments, private homes and commercial applications. The South African Bureau of Standards provides a range of standards covering the demands of the acoustics industry, from quality management systems to test methods for specific materials or parts. Some of the related SABS standards and publications in South Africa are as follows:
• SANS 3744: Determination of sound power levels and sound energy levels of noise sources using sound pressure – Engineering methods for an essentially free field over a reflecting plane.
• SANS 3743-1: Determination of sound power levels and sound energy levels of noise sources using sound pressure – Engineering methods for small, movable sources in reverberant fields Part 1: Comparison method for a hard-walled test room.
• SANS 140-1: Measurement of sound insulation in buildings and of building elements – Part 1: Requirements for laboratory test facilities with suppressed flanking transmission.
• SANS 11690-1: Recommended practice for the design of low-noise workplaces containing machinery – Part 1: Noise control strategies.
• SANS 11200: Noise emitted by machinery and equipment – Guidelines for the use of basic standards for the determination of emission sound pressure levels at a work station and at other specified positions.
• SANS 13474: Framework for calculating a distribution of sound exposure levels for impulsive sound events for the purposes of environmental noise assessment.
For a full list of acoustic standards and publications, visit this page on the SABS website: https://www.sabs.co.za/Sectors-and-Services/Sectors/acoustics/acoustics_sp.asp.
Specialised tip: Laboratories use two tests, namely structure-borne noise reduction and airborne noise reduction, to measure the amount of sound transmitted within a space.
Thanks and acknowledgement are given to www.sabs.co.za, www.floorworx.co.za, www.kirk.co.za, www.polyflor.co.za, www.traviata.co.za, www.paroc.com and www.jjflooringgroup.com for some of the information contained in this article.
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