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NEW HEARING PROTECTOR RATING STANDARD
APPROVED
(September 25, 2007) The Acoustical Society of
America announced the publication today of ANSI/ASA
S12.68-2007 American National Standard Methods of
Estimating Effective A-Weighted Sound Pressure
Levels When Hearing Protectors are Worn.
This standard will be valuable to managers,
industrial hygienists and hearing conservation
professionals responsible for selecting and
assigning hearing protectors for noise-exposed
workers: military and law-enforcement personnel;
manufacturers of hearing protectors; hearing
protection testing laboratories; acoustic
consultants; and regulatory agencies. Though
rating and computational methods have been
previously described in the literature, and
governmental publications and regulations, this is
the first time that an American National Standard
specifies such procedures.
This standard specifies three methods, in
ascending order of complexity of use and potential
accuracy, for the estimation of the sound pressure
levels that are effective when a hearing protector
is worn. The simplest of the methods is similar to
the well-known NRR, but diverges in two key
aspects: namely it can be used with A-weighted
sound pressure levels instead of requiring the use
of C-weighted levels, and instead of specifying a
single number at the 98th percentile, it provides
values for the 80th and 20th percentiles. This
standard is accompanied by an informational
spreadsheet programmed to perform the calculations
specified in the standard itself.
This Standard was developed by Accredited
Standards Committee S12, Noise, under operating
procedures accredited by the American National
Standards Institute (ANSI). These procedures assure
that the Standard represents the consensus of
opinion among those with a direct and material
interest in the subject matter. The standard was
drafted by a working group comprising experts from
all segments of the hearing conservation community.
This standard and many other national and
international noise standards can be obtained from
the Acoustical Society of America Online Store at:
http://asa.aip.org
Or, order by phone, fax or mail from:
Acoustical Society of America
35 Pinelawn Road, Suite 114E
Melville NY 11747 3177
Phone: 631-390-0215
Fax: 631-390-0217
Email: asastds@aip.org
ASA offers the full catalog of ISO/TC108,
ISO/TC43, and IEC/TC29 standards, as well as a wide
range of American National Standards on the topics
of Acoustics, Mechanical Vibration and Shock,
Bioacoustics and Noise.
The American National Standards Institute, Inc.
(ANSI) is the national coordinator of voluntary
standards development and the clearinghouse in the
USA for information on national and international
standards.
The Acoustical Society of America is a nonprofit
organization, founded in 1929. It is the premier
international scientific society in acoustics,
dedicated to increasing and diffusing the knowledge
of acoustics and promoting its practical
applications.
For Additional Information Contact:
Susan Blaeser
(631) 390-0215
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