MASC 2000

Unilateral Hearing Loss in Children

Nan K. Lukmire, M.Ed.
Donna M MacNeil, M.A.
Walter Reed Army Medical Center

This presentation will focus on the diagnosis, audiologic and medical management, amplification options and educational and psychosocial impacts of unilateral hearing loss in children. Included in educational options will be a discussion of the effectiveness of conventional and CROS hearing aids and personal and sound-field FM systems in the classroom environment. Several cases will be presented to illustrate some of the challenges facing audiologists and educators dealing with unilaterally hearing impaired children.

[The following links are provided for further information on unilateral hearing loss in children. -Editor]

The Combat Arms Earplug

Doug Ohlin, Ph.D
U.S. Army Center for Health Promotion and Preventive Medicine

For the dismounted soldier or marine, conventional hearing protection can interfere with the communication requirements of a mission when hearing protection is needed the most, i.e., firing weapons away from fixed firing points without the benefit of loudspeaker systems. The solution would be a non-linear hearing protector that would mitigate the hazard over a desired range, but marginally interfere with voice communications and detection of combat sounds such as vehicle noise, footfalls in leaves, closing of a rifle bolt, etc.

Dr. Armand Dancer and his colleagues at the French-German Institute have dramatically improved upon a low tech and inexpensive solution to this problem. Data will be presented and samples provided of an earplug design born of U.S./French collaboration. In the Combat Arms Earplug we finally have a hearing protector that protects without impairing military effectiveness.

Fitcheck Project Phase II

Wayne Loyborg, Hearing Conservation Consultant, CHPPM-Europe
CPT Rhonda Fleener, Landstuhl Regional Medical Center

In the first phase of this project, reported at MASC 1997, we checked attenuation of hearing protectors, using the Fitcheck,. Measurements were performed immediately after soldiers had finished firing for qualification. After firing they were instructed not to touch earplugs until the test was finished. Results showed attenuation for the rifle range group was 10 dB less at each test frequency, 250 Hz, 2000 Hz and 4000 Hz than for another group of soldiers who had been instructed in how to use earplugs.

In phase II, soldiers were instructed, in proper use of earplugs, during the range safety briefing just prior to firing for qualification. At the conclusion of each firing order the soldiers were told to leave earplugs in place and proceed to the test area where earplug attenuation was measured using the Fitcheck device. Test frequencies were 250 Hz, 2000 Hz, and 4000 Hz. Results were compared with the phase I soldiers who received no instruction on earplug usage just prior to firing for qualification.

The Role of Distortion Product Otoacoustic Emissions (DPOAE) in Assessment of Pseudohypacusis

David J. Rothman, MA CCC-A
MAJ Albert H. Gass, MS CCC
Ft. Bragg, North Carolina

False claims of hearing loss (pseudohypacusis) by Active Duty soldiers affect unit readiness and deployability. Since Distortion Product Otoacoustic Emissions (DPOAE) are sensitive to cochlear site of lesion and the overwhelming majority of service related hearing loss is due to cochlear damage, DPOAE should be an ideal objective test for distinguishing sensory hearing loss from pseudohypacusis. At Fort Bragg, we have validated the use of DPOAE as a part of an objective audiologic test battery to distinguish pseudohypacusis from hearing loss due to organic site of lesion. This test battery consists of tympanometry, acoustic reflex, acoustic reflex decay, and DPOAE in addition to comprehensive behavioral audiometric evaluation. Three patients, out of more than 100, presented with behavioral hearing loss and normal DPOAE results. Auditory Brainstem Response confirmed that hearing loss was not due to organic site of lesion in each case.

24 Months into the Future: Population-based Preventive Audiology Practice

Thomas M. Helfer
Hearing Conservation Program
US Army Center for Health Promotion and Preventive Medicine
DSN 584-3797 410-436-3797

Over the last 5 years the public health community has given significant attention to using outcomes analysis and epidemiologic inference as the evidence base for clinical practice guideline development and for healthcare quality improvement benchmarking. For almost a decade the USACHPPM has partnered with academic and research institutions and worked on epidemiologic analyses to develop an evidence-based practice of hearing loss prevention performance evaluation.

A statistical analysis software product of one of these collaborative efforts is being delivered to USACHPPM. The anticipated primary users drove the design of this product. The users are a multi-disciplinary clinical investigation team. The team includes subject matter expertise in clinical practice, clinical research, bio-statistics, and epidemiology.

This team is currently working to implement the product at USACHPPM to develop command health information for customers. This paper describes this team’s epidemiologic inference methods and related clinical data management activities to accomplish an evidence-based practice of hearing loss prevention and quality of care improvement in collaboration with primary customers.

The clinical data management and statistical analysis protocols used are in line with the Military Health System’s strategic information management infrastructure mandates. This will be a significant aid in the transfer of these methods to the other services’ preventive medicine and environmental health centers as well as transfer to the non-DOD health services sector for hearing conservation program evaluation.

Abstract: A task force of 900 Texas National Guard soldiers were given soldier readiness processing (SRP) at a remote field site on North Fort Hood. It was imperative that the medical SRP locate on-site to reduce soldiers’ time away from training, and to reduce traffic on the heavily traveled west range road. Because Fort Hood has no mobile test capability, the decision was made to contract services. This presentation considers the challenges involved when contracting hearing test services for large deployments. Elements of a successful product will be outlined and discussed; to include: equipment performance, employee performance, compliance with Army Hearing Conservation record keeping guidelines, and the ability to convert hearing test data into the Department of Defense format. This study suggests that contractors can perform very well in the field environment and deliver a quality product despite differences in equipment and software.