The following is an explanation of the
(7) HEARING CATEGORIES and the (5)
TEST TYPES used by Hearing
Conservation Services, Inc., to evaluate your audiograms. These are intended to
reflect sound audiological practice as sell as CLSHA rules and regulations.
When any test results do not fit the pattern, special notes will be made. Any
tine you have additional questions, please call us.
CATEGORY 1 - NORMAL HEARING.
Defined as a range of 0-25dB. This is where we went everybody. An individual could have
hearing in this range and still demonstrate a standard threshold shift (STS)
which would put him in Category 5.
CATEGORY 2 - NORMAL
HEARING THROUGH 2000Hz WITH VARYING DEGREES OF HIGH FREQUENCY LOSS IN ONE OR
BOTH EARS. This is a type of borderline category. You might consider
it a warning flag. Noise induced hearing loss usually begins in the higher
frequencies (3K Hz - 6K Hz); therefore, this individual merits monitoring.
If working in an area above 85 dBA, you should definitely wear ear protection.
CATEGORY 3 - DEFINITE
HIGH FREQUENCY LOSS.
These audios will show losses greater
than 25dB at 3K Hz - 6K Hz in both ears. Ordinarily this will be
a compensable loss. If this is a new employee (baseline audio), be very
careful in obtaining results. Baseline tests should be preceded by fourteen (14)
hours without exposure to workplace noise; hearing protectors may
used as a substitute for this requirement. Again, ear protection should be worn
by employees in any noise risk environment.
Categories 1, 2, &
are used for baseline audios ~
CATEGORY 4 - NO
CHARGE FROM BASELINE.
is evaluated using OSHA guidelines and standard audiologic principles. This is
a good category. It suggests the program is working.
CATEGORY 5 - STANDARD THRESHOLD SHIFT (STS). OSHA defines a STS as a change in hearing threshold
relative to the baseline audiogram of an average of 10dB or more at 2000, 3000,
and 4000 Hz in either ear. Any number of causes may result in a STS; one of them may
occupational noise exposure. When a CATEGORY 5
is reported to you, you need to assess the severity of the shift, the workplace,
the compliance with wearing of ear protectors, test conditions, noise exposure
prior to test, etc. We need to work together to minimize the number in this
CATEGORY 6 - MEDICAL REFERRAL. Due
to an individuals case history, possible pathology that may exist, the slope
of the audiogram, the relationship between ears, etc., a medical referral should
be made to an otolaryngologist, to our office, etc., for follow-up.
CATEGORY 7 - REVISED BASELINE (MEDICAL/NON-OCCUPATIONAL).
This category indicates a revised baseline due to an individuals case
history; continuous medical problems, or a shift from baseline due to a
non-occupational cause. (Effective 1/94).
Categories 4, 5, 6, &
are used for annual audios ***
(2) - ANNUAL;
(3) - RETEST;
- REVISED BASELINE (SIG IMP);
(5) - TEMPORARY THRESHOLD SHIFT