It doesn’t seem fair that buildings that possess appropriate acoustics almost always go unnoticed, while projects that underperform acoustic specifications are constant topics of discussion. Adding insult to injury, many of these failures come as surprises to both the design and construction teams who thought they had acoustics covered with lab tested, acoustically rated walls, ceilings and building components. Although it is to be expected that variations in the field will account for a 5 dB drop in performance from those measured on the ideal assembly in a laboratory, significantly worse performance can typically be traced to a failure to follow three simple checks:
There are over 70 acoustic rating systems, which are defined by ASTM, SAE, AAMA, ISO, NFPA, ECMA, IEC, MIL-STD, BS EN, AS/NZS and AS ISO standards with improved rating systems being continually developed as the science progresses. These same organizations publish stringent test procedures to be used to determine those ratings, each requiring specialized lab facilities and quality control procedures. A simple check of the accreditation status for the lab that produced your test report is assurance that the lab is qualified to perform those tests. In the United States, labs may be accredited for acoustics and other tests through the National Voluntary Laboratory Accreditation Program of the National Institute of Science and Technology. The NIST website gives a searchable listing of NVLAP accredited labs along with copies of their certifications. Since there are only 19 NVLAP accredited acoustic testing labs in the US and another four in Canada and Japan, verification of status is quick.