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SUPPLEMENTAL APPENDIX: NOISE EXPOSURE QUESTIONNAIRE
The NEQ developed by Megerson (2010) was used in this study to quantify subjects’
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noise exposure background (NEB). The NEQ specifically assesses nine categories of noisy
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activities by querying the frequency and duration of exposure. Responses were rated
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categorically and assigned a numerical value (frequency: daily=200; weekly=50; monthly=12;
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every few months=1; never=0; duration: 8 hrs or more=8; 4 to 8 hrs=6; 1 to 4 hrs=3; less than 1
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hr=1). These values were used to estimate the total number of hrs spent in a given situation over
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the past year. Exposure doses (D) using the following equation were computed for the nine noise
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activities:
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𝐶
𝐷 = [ ] × 100
𝑇
In the dose equation, C refers to the number of hrs/yr reported by the subject for the noisy
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activity. To calculate C for questions relating to occupational noise exposure, subjects report on
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average how many hrs/wk and how many wks they worked in a yr. For non-occupational noise
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exposures, C is the multiplication of the assigned numerical values for the frequency and
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duration of the noise exposure (e.g., weekly exposure to power tools for 1 to 4 hrs would yield
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C=50x3=150 hrs). T represents the number of hrs/yr at which the activity is considered
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hazardous using the NIOSH recommended exposure limit (REL) for noise (79 dBA with a 3-dB
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exchange rate is the annual equivalent of the NIOSH 85 dBA REL):
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𝑇=
8760
2(
𝐿−79⁄ )
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L is the continuous equivalent sound level in dB LAeq derived from the literature for that
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specific noise exposure type. The L for each of the nine noisy activities categories are as follows:
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power tools, 94 dB LAeq; heavy equipment/machinery, 97 dB LAeq; commercial
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sporting/entertainment events, 94 dB LAeq; motorized vehicles, 98 dB LAeq; small/private aircraft,
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91 dB LAeq; musical instrument playing, 87 dB LAeq; music listening via personal earphones, 76
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dB LAeq; music listening via audio speakers, 78 dB LAeq; occupational exposure, 90 dB LAeq (all
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from Megerson, 2010).
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Because the LAeq8760h is an estimate of the amount of noise exposure encountered in one
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yr, or 8760 hrs, the noise level of routine activities (e.g., shopping, eating, driving a car, etc.) not
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readily associated with high noise environments also needs to be taken into account and a dose
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percent needs to be calculated. The duration of the amount of time (C) spent engaging in routine
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activities is calculated as 8760 hrs minus the subject’s reported number of hrs spent in the nine
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noisy activity categories assessed by the NEQ (i.e., the remaining hrs in a year). The level (L) of
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routine activities was defined as 64 dB LAeq (Neitzel et al., 2004a,b).
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The ten doses were added arithmetically, resulting in a dose reflective of the overall
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amount of time spent annually in noisy environments relative to NIOSH dose requirements. A
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dose < 100% can be interpreted as not exceeding NIOSH recommendations and a dose > 100%
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can be interpreted as exceeding NIOSH recommendations of what is considered a safe listening
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environment (i.e., 79 dBA REL for 8760 hrs and a 3 dB exchange rate). The overall dose percent
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is necessary to compute the LAeq8760h using the following equation:
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𝐷
𝐿𝐴𝑒𝑞8760ℎ = [10 × log10 (
)] + 79
100
To demonstrate how individual responses on the NEQ affect the resulting LAeq8760h, two
examples of NEQ calculations are listed below:
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Example 1: Individual with a high NEB
Reported
hrs (C)
L
(LAeq)
Reference
hrs (T)
D
(%)
Never (0)
n/a
0
94
274
0%
Heavy equipment &
machinery
Never (0)
n/a
0
97
137
0%
Commercial sporting &
entertainment events
Weekly (50)
4 to 8 hrs (6)
300
94
274
109.59%
Motorized vehicles
Never (0)
n/a
0
98
109
0%
Small/private aircraft
Never (0)
n/a
0
91
548
0%
Musical instrument
playing
Daily (200)
1 to 4 hrs (3)
600
87
1380
43.49%
Music listening via
personal earphones
Every few months (1)
Less than 1 hr (1)
1
76
17520
0%
Music listening via
audio speakers
Daily (200)
Less than 1 hr (1)
200
78
11037
1.81%
Occupational exposure
Never (0)
0
90
690
0%
7659
64
280320
2.73%
Activity
Response
Power tools
Routine activities
Total Dose 157.63%
LAeq8760h
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48
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Example 2: Individual with a low NEB
Reported
hrs (C)
L
(LAeq)
Reference hrs
(T)
D
(%)
Never (0)
n/a
0
94
274
0%
Heavy equipment &
machinery
Never (0)
n/a
0
97
137
0%
Commercial sporting &
entertainment events
Every few months (1)
1 hr to 4 hrs (3)
3
94
274
1.1%
Motorized vehicles
Every few months (1)
Less than 1 hr (1)
1
98
109
0.92%
Small/private aircraft
Never (0)
n/a
0
91
548
0%
Musical instrument
playing
Never (0)
n/a
0
87
1380
0%
Music listening via
personal earphones
Every few months (1)
Less than 1 hour (1)
1
76
17520
0.01%
Music listening via
audio speakers
Daily (200)
Less than 1 hour (1)
200
78
11037
1.81%
Occupational exposure
Never (0)
0
90
690
0%
8555
64
280320
3.05%
Activity
Response
Power tools
Routine activities
Total Dose 6.89%
LAeq8760h
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