CAOHC Newsletter: UPDATE
You Checked Your Audiometer Today?
by Susan Cooper Megerson, MA CCC-A
of the effectiveness of your Hearing Conservation Program depends
upon the accuracy of your audiometric testing efforts. In turn,
the validity of the audiometric testing results is dependent upon
several factors, one of which is the adequate functioning of your
equipment. As the OHC performing the audiometric test, you are responsible
for proper calibration and appropriate documentation of your audiometer.
As discussed in your CAOHC training course, the Occupational Safety
and Health Administration (OSHA) and good practice require that
three types of audiometer calibration be conducted:
Check: The operation of the audiometer must be checked daily
- prior to audiometric testing. First, the output of
the audiometer is checked by conducting an audiometric test
for a person with known, stable thresholds or utilizing a "bio-acoustic
simulator" device. Next, the tester must listen to the
output of the audiometer to make sure it is free from distorted
or unwanted sounds. Deviations of 10 dB or greater on the output
check or detection of static or unwanted sounds on the listening
check require that an acoustical calibration be performed prior
Calibration: The acoustical calibration must be performed
at least annually. This is a more objective form of the
functional check conducted using an acoustic calibration system.
Output deviations of greater than 10 dB or any other unusual
variations require that an exhaustive calibration be performed.
Calibration: An exhaustive calibration must be conducted
at least every two years in accordance with specifications
of the American National Standards Institute (ANSI). As the
name implies, this calibration entails a more in-depth analysis
of the audiometers function and may include adjustments
according to ANSI specifications.
are many resources available to you should you need assistance or
guidance in maintaining your audiometric equipment:
HEARING CONSERVATION MANUAL: See Chapter VII for
a more detailed description of calibration requirements and
recommended protocols. Appendix VII includes samples of various
audiometer calibration forms, courtesy of a number of CAOHC
Course Directors, which may be useful in your day-to-day documentation.
Course Director or Professional Supervisor: Be sure to review
calibration procedures and documentation with your professional
supervisor (the audiologist or physician responsible for reviewing
audiograms and determining referrals/follow-up). Its best
to identify your "quality control" procedures in advance,
so that equipment problems are detected and resolved prior
to testing. As we all know, a few minutes spent on prevention
is well worth avoiding the costly consequences of following-up
on inaccurate results and retesting employees.
Service Provider: Ask your professional supervisor or audiometer
supplier if acoustic/exhaustive calibration services are available.
Many will come to your location and provide the service on-site.
If you must ship your audiometer for annual calibration or repair,
pack carefully, and dont forget to include earphones,
the response switch and all connecting cords, so that the complete
system can be evaluated.