Iowa Administrative Code › Agency 876 - Workers' Compensation Division › Chapter 8 - Substantive and Interpretive Rules › Rule 876-8.11 - Apportionment of Age-related Loss for Occupational Hearing Loss Claims

Current through Register Vol. 47, No. 3, July 24, 2024
(1)
Effective date.
This
			 rule is effective for claims for occupational hearing loss filed on or after
			 July 1, 1998.
(2)
Purpose.
The purposes of this rule are to adopt tables and the
			 method for calculating age-related hearing loss and to adopt a worksheet for
			 apportionment of age-related hearing loss for occupational hearing loss
			 claims.
(3)
Table.
In 1972 the National Institute for Occupational Safety and Health (NIOSH)
			 published the Criteria for a Recommended Standard: Occupational Exposure to
			 Noise (NIOSH Publication No.73-11001). Table B-1, page I-16, provides the Age
			 Corrections Values to be Used for Age Correction of Initial Baseline Audiograms
			 for Males and Table B-2, page I-17, provides the Age Corrections Values to be
			 Used for Age Correction of Initial Baseline Audiograms for Females. These NIOSH
			 tables are used to calculate the correction value for age for males and females
			 for 500, 1000, 2000 and 3000 hertz.
For example, the age correction for a male 21 years of age is
				10 decibels at 500 hertz, 5 decibels at 1000 hertz, 3 decibels at 2000 hertz
				and 4 decibels at 3000 hertz. The correction for age is 5.50 decibels (the sum
				of 10+5+3+4 divided by 4).
The following table is to be used to determine an employee's
				age-related change in hearing level during the period of employment. To
				determine the age-related change in hearing level in decibels during the period
				of employment, subtract the value shown in the table for the employee's age at
				the beginning of employment from the value shown in the table for the
				employee's age on the date of injury.
Note: This table should not be used to compute standard
				threshold shift as required by rules of the Occupational Safety and Health
				Administration or Iowa occupational safety and health administration.
Age in
						  Years
Correction in
						  dB
Males
Females
20 or younger
5.50
7.25
21
5.50
7.75
22
5.50
7.75
23
5.50
8.00
24
5.75
8.00
25
6.00
8.25
26
6.25
8.50
27
6.50
8.75
28
6.75
8.75
29
6.75
8.75
30
6.75
9.00
31
7.25
9.25
32
7.50
9.50
33
7.50
9.75
34
7.75
9.75
35
8.00
10.00
36
8.25
10.25
37
8.75
10.25
38
8.75
10.50
39
9.00
11.00
40
9.00
11.00
41
9.25
11.25
42
10.00
11.50
43
10.25
11.75
44
10.25
12.00
45
10.50
12.25
46
10.75
12.50
47
11.00
12.50
48
11.50
13.00
49
12.00
13.25
50
12.25
13.50
51
12.25
13.75
52
12.75
13.75
53
13.25
14.25
54
13.50
14.50
55
14.00
15.00
56
14.25
15.00
57
14.50
15.25
58
15.25
15.75
59
15.50
16.00
60 or older
16.00
16.25
(4)
Apportionment.
The apportionment of age-related hearing loss
			 shall be made by reducing the total binaural percentage hearing loss as
			 calculated pursuant to Iowa Code section 85B.9(3)  by the same percentage as the
			 decibels of age-related change in hearing level occurring during the period of
			 employment bears to the total decibel hearing level in each ear.
Age-related hearing loss is apportioned using the results of
				the audiogram determined to be the proper audiogram for measurement of the
				employee's hearing loss on the date of injury by using the following
				steps:
1. Separately for each ear,
			 compute the average of the employee's decibel hearing levels at 500, 1000,
			 2000, and 3000 hertz for that ear.
2. Separately for each ear, compute the
			 percentage loss for each ear.
3.
			 Compute the employee's age-related change in hearing level in decibels during
			 the period of employment using the table in subrule 8.10(3).
4. Separately for each ear, divide the result
			 of step 3 by the result of step 1 to compute the age-correction factor for that
			 ear.
5. Separately for each ear,
			 multiply the total percentage hearing loss in that ear calculated pursuant to
			 Iowa Code section 85B.9 by the age-correction factor for that ear.
6. Separately for each ear, subtract the
			 result obtained in step 5 from the total percentage hearing loss in that ear to
			 obtain the age-corrected hearing loss for that ear.
7. Multiply the age-corrected hearing loss in
			 the better ear as calculated in step 6 by 5 and add the percentage hearing loss
			 in the worse ear.
8. Divide the
			 result obtained in step 7 by 6 to obtain the age-corrected binaural percentage
			 hearing loss.