New employees should have a baseline audiogram
within six months of starting their high noise job unless a mobile test van is used, in which case the audiogram may be conducted within one year of starting in the job.
When treatment success was reviewed based on the baseline audiogram
types of patients, mean hearing gain was identified to significantly differ among the groups (p=0.018).
The baseline audiogram
serves 6 10.5 50 87.7 as a comparison for future audiograms, helping to determine hearing improvement or loss.
Neither patient had had a previous audiogram available to confirm an objective change in hearing thresholds, but having a baseline audiogram
on hand for comparison is rather rare.
The first step in the prevention process is to obtain a baseline audiogram
. The baseline audiogram
serves as the reference point for all subsequent hearing tests and allows for changes in hearing sensitivity at a given frequency to be documented.
The Department of Defense uses the Occupational Safety and Health Administration's definition of an STS8: a change in hearing threshold relative to the baseline audiogram
of an average of 10 dB or more at 2000 Hz, 3000 Hz, and 4000 Hz in either ear.
The first is that the employee experiences a standard threshold shift of at least 10 decibels in one or both ears, compared with the most current baseline audiogram
(6) averaged at 2,000, 3,000, and 4,000 hertz.
Ototoxic threshold shift from the initial baseline audiogram
was defined as: (1) [greater than or equal to] 20 decibel (dB) decrease at any one test frequency, (2) [greater than or equal to]10 dB decrease at any 2 adjacent frequencies, or (3) loss of response at 3 consecutive frequencies where responses had previously been obtained.
Hearing protection is also mandatory for employees who nave been exposed to 85 dB(A) noise levels if they did not have a baseline audiogram
, and for workers who experience standard threshold shifts--an average shift from baseline hearing levels of 10 dB or more at the audiometric frequencies of 2,000, 3,000, and 4,000 Hz.
The patient's actual baseline audiogram
(solid line) would be provided on the same graph with gray shading indicating the "speech banana." Figure 2 shows data using this format from case study 1.
This includes Soldiers without a reference baseline audiogram
or whose last periodic audiogram is greater than one-year old.
STS is defined by the Occupational Safety and Health Act (OSHA) as an average l0-dB or greater shift from the baseline audiogram
at 2.0, 3.0, and 4.0 kHz for either ear.