Standards on Occupational Noise Exposure
Measurements and Hearing Protectors
Behar, P. Eng., CIH and Lee Hager
Standards try to help
manage the world we live in and the things
we do in a manner that is repeatable and
manageable. The standards process ensures
that when we buy a pound of coffee, it’s
really a pound, and that a quart of milk
is really a quart. People sometimes ask,
what are standards? Why do we need them?
Who writes them, and who’s responsible
for publishing them and keeping them up
Wikipedia, the free
states that a technical standard is, “...an
established norm or requirement.”
It’s usually a formal written document
that establishes uniform engineering or
technical criteria, methods, processes
Standards are “best
practices” that describe how to
consistently do important things in a
way that is understood and repeatable—things
like electrical standards, for example,
describe how houses are to be wired (so
the electrician knows which wire is which)
and what is meant by “117V AC”
(so the microwave manufacturer puts the
right parts inside their appliance).
provide specifications and descriptions
about “how to.” Most often
they deal with how to measure, or how
to build or, finally, how to manage. In
this chapter, the standards of interest
describe how to measure workplace noise
exposure, how to estimate the effect of
noise exposure on one’s hearing,
and how to determine the effectiveness
of hearing protectors.
Some standards go beyond
measuring, and describe how to apply information.
The hearing protector evaluation standards
described here provide such an example.
Some standards also provide direct guidance
to end users, for example, on how to select
appropriate hearing protection devices
for certain kinds of noise levels, or
how to use and care for these devices.
to recognize that standards development
is an ongoing process. The people who
develop standards are constantly working
to improve and update these documents
to reflect new scientific findings, new
technologies, or improved practices in
their areas of interest. The standards
discussed in this chapter may undergo
revision at any time, and the reader is
encouraged to investigate the most recent
revision for the latest information.
Experts in a given field
determine that there is a need to establish
a “norm” or standard practice.
This might be a need to conduct some activity
consistently and reliably, so that when
this activity is done by different groups
of people, (within the same or different
countries) the results from each group
can be compared “apples-to-apples.”
It may be a need to specify important
guidelines, such as how loud emergency
warning signals should be in offices as
opposed to manufacturing environments.
The experts decide when it’s time
to develop a standard.
Standards are typically
developed by groups of subject matter
experts (SMEs). These are people with
specific expertise on the topic of interest.
Most standards development committees
(in the US, these are referred to as “Working
Groups”) are ad hoc, meaning that
they assemble to write a particular standard
on a specific topic. Experts are volunteers
and work on an honorarium basis (unpaid).
Once the standard has been approved, the
SME may be dissolved and assembled again
either for a revision or for writing another
standard on the same topic. Decisions
within the committee are typically determined
by consensus, so that everyone working
on the standard must agree on what is