Custom moulded earplugs versus foam canal tips for the

August 3, 2013

Center for Man in AviationYuval Steinman

Human Factor Researcher

Custom moulded earplugs versus foam canal tips for the Communications Earplug (CEP):

A summery of comparison studies

Royal Netherlands Air Force2August 3, 2013CUSTOM MOULDED EARPLUGS

Disclosure Information84th Annual AsMA Scientific Meeting

Yuval Steinman

I have no financial relationships to disclose.

I will not discuss off-label use and/or investigational use in my presentation


Introduction I

Problems with the CEP’s foam canal tips (f-CEP) (survey results)15% rated the comfort of the CEP with foam tips as goodComplaints about the CEP

Irritation Pressure in ear canal – pain Foam tips do not fit Proper insertion takes too long Further decrease in comfort after 2 hours use Falls out Rigid cables Hygiene


Introduction IICEP is supplied with 3 types of foam tips:Standard Slim Short

The absence of proper guidance in the use of the CEPAircrew do not know how to choose the right foam tip Insertion of the foam tip is not done correctly


Introduction IIICustom moulded ear plugsTailor made to match the contour of the earSoftFlexibleComfortableEasy to insert

Are custom moulded ear plugs the solution for our CEP problems???


Methode IPopulation 40 subjects (pilots and loadmasters)Chinook, cougar and Apache

Currently evaluating NH90

Helmet typesHGU-56/P

IHADSS

Alpha 200

Alpha 900


Method IIQuestionnaireLikert scaleFive Likert items

Open questions Aspects Earplug fit

Earplug comfort

Usability

Speech intelligibility

User feedback

Questionnaire filled after adaptation period (>10 hours)


Method III Attenuation performance using the real-ear

attenuation at threshold (REAT) method


ResultsComparison between CEP with custom moulded earplug and CEP with foam tips

Aspect Much worse Worse No difference Better Much better

Earplug fit 5 5 30

Earplug Comfort

5 30 5

Usability 6 10 25

Speech intelligibility

35 5


Results Noise attenuation HGU-56/P (n=10)


Results Noise attenuation Alpha 200 (n=10)


Results Noise attenuation IHADSS (n=10)


Discussion The use of CEP, in both configurations, improved overall attenuation significantly compared to the helmets alone.

c-CEP performed better then f-CEP Fit Comfort Usability

No difference was found between the two configurations

Noise attenuation Speech intelligibility


Discussion II10% of the participants reported a decrease in fit, comfort and usability when using the c-CEP.

Causes:Earplugs that were not fabricated correctlyDid not receive instruction in proper use of the c-CEPDiscomfort was related to helmet fit and ear cup depth (cushion)


Steps taken Introduction of c-CEP in the RNLAF Helmet fit is performed with CEP Information flyers/demonstrations for the aircrew in

proper use of the c-CEP How to put the helmet on

If needed adjustments are made to the custom moulded earplug

Contact with manufacturer to improve custom moulded earplug design


The future Improve the manufacturing procedure of the custom moulded earplugs

Ear canal imprints Production if the earplug CEP as part of the helmet


Documents

Custom moulded earplugs versus foam canal tips for the