Medical Research and Materiel Command U.S. Army … · Artillery and Mortar M119 105MM Howitzer -183 dBP M224 60MM Mortar – 185 dBP. Medical Research and Materiel Command U.S. …

Medical Research and Materiel CommandMedical Research and Materiel CommandU.S. Army U.S. Army AeromedicalAeromedical Research LaboratoryResearch LaboratoryFort Rucker, AlabamaFort Rucker, Alabama

Hearing Protective DeviceField Attenuation Estimation Systems

Round Robin EvaluationsRound Robin Evaluations

William A. AhroonKel H KratzerKel H. KratzerAngela N. FulbrightM. Joel JenningsMichelle M. VincentKara M. Cave

The views expressed in the document are those of the author and do not necessarily reflect the official policy or position of the U.S. Medical Command, the U.S. Department of the Army, the U.S. Department of Defense, or the U.S. Government.


Hearing Protective DeviceField Attenuation Estimation Systems

NIOSH HPD Well-Fit™

M. Joel JenningsFort Bliss, TX

The views expressed in the document are those of the author and do not necessarily reflect the official policy or position of the U.S. Medical Command, the U.S. Department of the Army, the U.S. Department of Defense, or the U.S. Government.


Introduction to Round Robin StudyTh f th k h i t t d bi l ti f fiThe purpose of the workshop is to report on a round-robin evaluation of fivehearing protective device (HPD) field attenuation estimation systems (FAES)(or fit-check systems) from several commercial vendors and one governmentagency. The systems were used by Army audiologists as an adjunct to theirg y y y y g jnormal hearing conservation programs. Routine audiometric assessments areconducted as part of the Army Hearing Program. When a Soldier is determinedto have a standard threshold shift during these assessments, follow-up testingis conducted by a certified audiologist In addition to standard audiometricis conducted by a certified audiologist. In addition to standard audiometrictesting, this follow-up appointment includes an examination of the Soldier’sHPD and additional training on the proper care and use of the HPD. Theround-robin evaluation inserted HPD FAES as a tool in the HPD retrainingprocess. Each Army audiologist engaged in the round-robin evaluations willprovide a review of the team’s results and observations from one of the FAES.


Round Robin Candidates

• E-A-Rfit™ 3M Company

• FitCheck™ Michael and Associates, Inc.

• HPD Well-Fit™ NIOSH, Cincinnati

• INTEGRAFit Workplace INTEGRA, Inc.

• VeriPRO™ Howard Leight® by Honeywellg y y


NIOSH HPD Well-FitWhat were we doing?What were we doing?

Subjectively evaluating the product• Ease of use for examiner and end user• Ease of use for examiner and end user• Clarity of reporting• Time requirements

Objectively measuring the fit of user’s hearing protection• Measure first with self-reported HPD and no instruction• Re-fit (if low PAR) with proper plug and/or instruction( ) p p p g


Fort Bliss, TexasHome of the 1st Armored Divisiono e o e o ed s o

“Old Ironsides”


Tankers

M1A1 Abrams Main gun 176 dBPgM240 7.62mm 155 dBPDriver position 103 dBA @ tactical idle


Artillery and Mortar

M119 105MM Howitzer -183 dBP

M224 60MM Mortar – 185 dBP


Digital HPD!!!


Nothing New….


Aviation

UH-60 Blackhawk – 106 dBA


Infantry

HMMWV – 88 dBA @ 40 mphM2A2 Bradley – 115 dBA @20 MPHMRAP 85+ dBA @ low idleMRAP – 85+ dBA @ low idle

M16 5.56 mm – 157 dBPM9 9mm – 157 dBPM249 SAW 5.556 mm – 159.5 dBPM60 7.62mm – 155 dBP


Plugs Tested

Howard Leight Fusion

Combat Arms3M

Triple Flanged

Elvex Quattro


Default HPD

HPD Well-Fit is distributed with files that must be imported that include default

t ti d i i l diprotection devices, including EAR Classic, Speiran AirSoftand Fusion, Moldex PuraFitand Custom Protect Ear dB Blocker

Currently, users are unable to add their own data for HPDadd their own data for HPD.


Components


OperationS t St dSet-up your Study

• Default Test Method•Default Protector•A-Weighted Noise g•Prediction Percentile

Multiple Studies allows for organizations to select differentorganizations to select different defaults, for multiple groups within the organization, e.g. aviators, infantrymen, etc.


OperationSet Up Your locationSet Up Your location

Helpful if your organization has multiple locations


OperationSet Up Your SubjectsSet Up Your Subjects

Can be done ahead of time if you have a list of employees that will be tested


OperationSet Up Your SubjectsSet Up Your Subjects

Subjects can also be added individually at the time of testing if not set up ahead of time.


Operation

Sound Check –

Examiner can listen to left and right headphones to determine proper function. Should hear an 80 dB tone.

Directions for calibration could not be found on the system that we evaluated.


OperationStart New Fit TestStart New Fit Test populates the deafultvalues entered during the setup.


Operation


Operation


Operation

Unoccluded:

One third octave band noise isOne-third octave band noise is presented binaurally, beginning at 80 dB SPL. The subject scrolls downward on the scroll wheel of the mouse until they stop hearing the sound (threshold). The NBN then increases by 10-20 dB and theincreases by 10-20 dB and the process is repeated until three consistent responses are recorded.


Operation

Occluded –

Procedure is repeated in the same manner as before with earplugs in place.

A window will appear after hitting “start” in the occluded screen that gives you 2 minutes to have the subject insert their protectors.protectors.


ResultsO l d d th h ldOccluded thresholds are subtracted from unoccluded thresholds to obtain REAT values.

IN addition, PAR values are displayed in the reportreport.


Pros

• Easy instruction• Quick test to perform (average of about 5 minutes)• Can be performed on persons with hearing loss• NBN helpful with tinnitus• Uses binaural presentation*


Desired Improvements

• Software has glitches that cause crashes that need to be worked out.N bilit t t t thi b t l• No ability to test anything but earplugs

• Eliminate the 2 minute wait screen on occluded • All new test subjects should default to

unoccluded test firstL d t il d t il bl f t t bj t• Less detailed report available for test subject

• Uses binaural presentation*


Conclusions

Shows promise in terms of speed and ease of use for end use, but needs some refinement of reporting mechanism Could also use an optionreporting mechanism. Could also use an option for unilateral testing, and report format should be configurable to the consumer’s desires.configurable to the consumer s desires.


POINT of CONTACT

M. Joel [email protected]

William A. Ahroon, [email protected]

Documents

Medical Research and Materiel Command U.S. Army … · Artillery and Mortar M119 105MM Howitzer -183 dBP M224 60MM Mortar – 185 dBP. Medical Research and Materiel Command U.S. …