Download Asymmetric Hearing Loss in Career Firefighters

Asymmetric
Hearing
Loss
in
Career
Firefighters
University of California
San Francisco
Stephanie
Marie
Phelps,
RN,
MS,
Dal
Lae
Chin,
RN,
PhD,
OiSaeng
Hong,
RN,
PhD
University
of
California,
San
Francisco
Results
Introduc4on
•  Firefighters are exposed to intermittent loud
noise that causes hearing loss.
•  Asymmetric hearing loss (AHL) negatively impacts
spatial hearing, a critical aspect for firefighters’
work.
•  Individuals with AHL have difficulty determining
the direction, distance, and movement of a
sound’s source (Noble & Gatehouse, 2004).
•  AHL can cause hearing problems in background
noise.
Table 2. Prevalence of AHL
•  AHL: hearing threshold difference greater than
15dB at 0.5kHz, 1kHz, or 2kHz OR 30dB at 3kHz,
4kHz, or 6kHz between two ears (AAO-HNS, 1997)
Audiometric
Frequency
(kHz)
n
Valid
%
0.5
14
3.3
1
5
1.2
2
15
3.5
3
12
2.8
4
12
2.8
6
18
4.2
Total
76
17.8%
Table 1. Characteristics of participants (N=425)
Variable
Objec4ves
1.  Identify the prevalence rate of AHL.
2.  Compare mean hearing threshold levels
between ears.
3.  Discuss the importance of effective hearing
conservation programs for firefighters.
Methods
•  Participants: A convenient sample of 425
firefighters from 35 fire departments in three
states (CA, IL, IN) in the U.S
•  Measures
•  Pure-tone audiometry (0.5-8kHz) for both
ears by CAOHC certified medical staff
•  Internet-based self-administered survey
•  www.sirenresearch.com
•  demographic and work-related questions
•  perceptions of hearing loss
•  history of occupational injury
• Data was analyzed using SPSS 17
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Conclusion
Results
Mean
(SD)
Age
(Years)
44.8
(8.0)
Years
worked
in
the
fire
service
17.1
(8.0)
%
Ethnicity
(Caucasian)
80.3
Gender
(Male)
92.0
Reported
daily
exposure
to
loud
noise
when
working
as
a
FF
51.3
Use
of
hearing
protec4ve
devices
(%
of
4me)
in
the
fire
service
33.8
Type
of
hearing
protec4on
used
Ear
plugs
Ears
muffs
Both
plugs
and
muffs
Fingers/no
hearing
protec4on
29.2
23.1
1.2
46.5
Self‐reported
hearing
problem
(Yes)
29.6
Believe
good
hearing
is
important
to
perform
firefighter
du4es
96.0
Perceived
hearing
loss
as
a
contributor
to
occupa4onal
injuries
or
safety
problems
90.8
•  Of 425 participants, approximately 13% exhibited
AHL.
•  The left ear showed significantly poorer hearing
ability at frequencies of 2–6 kHz than the right
ear (p<0.05).
•  Current use of hearing protective devices (33.8%)
among firefighters is far lower than 100% use to
prevent hearing loss.
•  Effective hearing conservation program for
firefighters is warranted.
NOTE:
Fifeen
firefighters
met
the
asymmetry
criteria
in
more
than
one
frequency
and
are
counted
more
than
once
in
the
above
table.
References
Firefighters
who
met
at
least
one
%
of
the
asymmetry
criteria
(Yes)
Total
53
12.5%
Table 3. Paired sample t-test to compare mean
hearing threshold levels between ears
P‐value
•  American Academy of Otolaryngology-Head and Neck Surgery
(AAO-HNS) (1997). Otologic Referral Criteria for Occupational
Hearing Conservation Programs. Alexandria, VA.
•  Noble, W., Gatehouse S. (2004). Interaural asymmetry of
hearing loss, Speech, Spatial and Qualities of Hearing Scale
(SSQ) disabilities, and handicap. International Journal of
Audiology, 43 (2), 100-114.
Pairs
(L‐R)
in
test
freq
(kHz)
Mean
diff
(SD)
t
(df)
0.5
‐.3
(7.2)
.8
(423)
.44
1
‐.1
(6.1)
.4
(423)
.69
• Source of Funding: Federal Emergency Management Agency
(FEMA), U.S. Department of Homeland Security; Principal
Investigator= Hong
2
.9
(8.0)
2.3
(424)
.02
• Partnered fire departments in CA, IL, and IN
for their support and participation.
3
2.0
(10.7)
3.8
(424)
<.001
4
2.4
(13.1)
3.8
(422)
<.001
6
3.2
(13.3)
4.9
(424)
<.001
8
.7
(13.3)
1.0
(413)
.32
Acknowledgements
Contact
Stephanie Marie Phelps, RN, MS
[email protected]