Presentation on theme: "Hearing Conservation Update 14 JAN 2015 LCDR Andrew Hayes"— Presentation transcript:
1Hearing Conservation Update 14 JAN 2015 LCDR Andrew Hayes
2Naval Air Forces Top Ten Aeromedical Issues (2014) Spatial DisorientationFatigue MitigationHypoxia & DCS UASUAS operator aeromedical standards/waiversHearing ProtectionWhole-body vibration leading to M/S injuryMotion sicknessVision Enhancement / ProtectionEMALS / Magnetic Environment ExposureCBRNE
3“Noise and Vibration”This is a recommended brief given annually for aircrew as suggested in OPNAVINST Appendix E, Level D,Naval Aviation Survival Training Program Adjunctive Annual Training.
4Learning Objectives Discuss Anatomy and Physiology of the Ear Types of Ear DisordersNoise MeasurementAudiometric InterpretationHearing Protection Products in Naval AviationFuture Hearing Protection ProductsNavy Audiology Specialty Leader Update and 2dMAW Hearing Conservation InitiativesState the Learning Objectives for Noise
5Anatomy and Physiology of the Ear Three divisions of the human ear 1. Outer ear: acoustic energy 2. Middle ear: mechanical energy 3. Inner ear: hydroelectric energyIdentify the three parts of the ear and how energy transfers between each of the three divisions.The hearing mechanism has three components:1. Outer ear2. Middle ear3. Inner earHow sound energy travels through the three parts of the ear:The aircrew member does not need to know the names of each anatomical structure but should realize that energy is transfer through various conversions before it is “heard”. Acoustic energy, in the form of sound waves, is channeled into the ear canal by the pinna. Sound waves hit the tympanic membrane and cause it to vibrate, like a drum, changing it into mechanical energy. The malleus, which is attached to the tympanic membrane, starts the ossicles into motion. The stapes moves in and out of the oval window of the cochlea creating a fluid motion or hydraulic energy. The fluid movement causes membranes in the Organ of Corti to shear against the hair cells. This creates an electrical signal, which is sent up the Auditory Nerve to the brain. The brain interprets it as sound.3.1.2.
6Ear Disorders Sensorineural (Permanent) Hearing Loss Conductive (Temporary)Hearing LossExplain that hearing loss can be temporary or permanent in nature. This illustration points out that temporary hearing loss is limited to the outer and middle ear while permanent hearing loss is limited to the inner ear.Conductive Hearing Loss = Low Frequency = Outer or Middle Ear = TemporarySensorineural Hearing Loss = High Frequency = Inner Ear = PermanentMixed Hearing Loss = High and Low Frequency = Outer or Middle and Inner Ear = Conductive portion of HL is treatable, Sensorineural portion is permanent
7Ear Disorders: Noise induced hearing loss Damaged Hair Cells in the high frequency region of the cochleaExplain the Noise Induced Hearing Loss theory to the students: First sharp cochlear turn occurs at about this point. The hydrodynamics of this phenomenon suggests that a large amount of turbulence occurs at this specific point. This may cause significant overstimulation of the basilar membrane at around 4000 Hz.Other theories as to why Noise Induced Hearing Loss causes damage in high frequencies:2. Acoustic transfer function of the outer ear: Research has correlated the freq of the audiometric notch with the freq of ear canal resonance3. Foyer carpet phenomenon: these hair cells are lined up across from footplate of stapes, and get blasted first and foremost from all noise exposure, regardless of frequencyUndamaged Hair Cells in the cochlea
8Noise MeasurementYou can monitor hazardous noise with your smart phone microphone using sound level meter apps, accurate through 120dBA.
9Allowable Noise Exposures* Noise MeasurementAllowable Noise Exposures*Describe noise levels in the cockpit and flight deck in all category of aircraft.Point out that if hearing protection is worn correctly, this graph will help one determine the duration of time one can be exposed to such noise levels before a Noise-Induced Hearing Loss is evident.Highlighted in red are the dB levels that exceed the allowable level in a 12 hour shift.Hearing protection extends the duration of time one can be exposed to hazardous noise (i.e., permissible time limits) if worn correctly.*American Conference on Governmental Industrial Hygienists (ACGIH) Threshold Limit ValueFor Official Use OnlySlide courtesy of NAVAIR: PMA 202
19Audiometric Interpretation Example of an STS comparing Annual (2009) to Reference (2001)Member demonstrates a MODERATE (55dB)NOISE-INDUCED HEARING LOSS in BOTH EARSInterpret these DD 2216 results for the student. This Annual Audiogram (DD 2216 form) indicates that the member has sustained a Significant Thresholds Shift as of 30JAN2009 compared to a reference test established on 6OCT Point out that the member’s hearing has progressed from within normal limits in both ears to a moderate Noise Induced Hearing Loss in both ear (i.e., a “noise-notch” centered around 4,000 Hz). This by definition is an STS in both ears (i.e., “yes” in block 15d) that now must be re-evaluated to determine if the member has a PTS (permanent) or TTS (temporary).Annual Audiogram (DD 2216 form)
21< 30 dB in the better ear Student NavalAviator Applicants(MANMED 15-86)<25<25<25<45<55NA<25<25<25<45<55NA< 30 dB in the better ear< 50 dB in the worse ear@ 2000 Hz
22Class I Aviation Personnel < 30 dB in the better ear (MANMED 15-85)<35<30<30NANANA<35<30<50NANANA< 30 dB in the better ear< 50 dB in the worse ear@ 2000 Hz
23US Navy Flight Deck Hearing Protection and Communication Products Currently Being Deployed by Aegisound
24AegisoundRecipient of >$30M in US DoD R&D investment since ATI inception in 199715+ advanced and patented products developed and transitioned to production (50+ SBIR programs, R&D contracts, and transition programs)Prime contractor to the Navy and Air Force, subcontractor to Lockheed MartinProducing hearing protection and communication systems for US Navy Flight Deck Maintainers
25US Navy Flight Deck Hearing Protection and Communication Products Currently Being Deployed
26DC250,000+ DC2 sets sold for Navy flight deck maintainers hearing protectionDC2 ( ) single hearing protector can be worn with generic or custom molded earplugsCompatible with legacy cranial (bump-cap)Designed for use with the APC-2G next generation cranialNSN assignedDC2
27CTE30X + DC2 CTE30X DC2 CTE30X (05-001003) + DC2 (05-028001) Both products are US Navy Flight Deck specification PMA /R4 compliant6,000 CTE30X custom molded earplug sets sold ( ) for Navy flight deck maintainer’s hearing protectionCTE30X snaps into DC2 earcups for integrated double hearing protectionCTE30X recommended in NAVAIR (Aircrew Personal Protective Equipment)Compatible with legacy and future maintainer head protection productsCTE30XDC2
28Argonaut® DHP Communication Argonaut® DHP Comm. HeadsetDelivered headsets to NavyDelivering headsets to Navy inDigital Noise Canceling MicrophoneIntegrated double hearing protectionBoth custom (LPCCE) and generic communication earplugs are availableCompatible with legacy and APC-2G maintainer head protection productsProvides excellent speech intelligibility in extreme ambient noise fieldsArgonaut® DHPComm. Earplugs
29Low Profile CCE Developed based on request from MCAS New River Same digital manufacturing process and material composition as previously qualified CTE30XLow Profile design avoids earcup interference – permits replacement and interchangeability with foam tipsSold 600+ in to Marines, Coast Guard, etc.
30F-35 Maintainer Hearing Protection and Communications Systems Currently Being Deployed(DANR DHP & DANR DHPC - Triple Hearing Protection)
31Protection + Communication DANR DHP / DANR DHPCDigital Active Noise Reduction (DANR) Double Hearing Protection (DHP) with and without modular communications (C)Digital Noise Canceling (DNC) microphoneCustom molded DANR earplugs deliver a third layer of hearing protection with communications (no speakers are in the headset)NAVSEA approved, rechargeable lithium ion battery and charger options600 DANR DHP (non-comm) kits sold and delivered to LM201 DANR DHPC (comm enabled) kits sold and delivered to LMProtection + Communicationin 150 dB
34DANR DHPC Speech Intelligibility Comparison In a typical 130 dB jet noise environment…With the status quo communication headset, you can understand random words,outside of any context,0% of the timeWith the DANR DHPC headset, you can understand random words, outside of any context,77% of the time!
35DANR DHP & DHPC Hearing Protection Comparison In a typical 130 dB jet noise environment…You can wear the status quo for 35 seconds before you are at risk for long term hearing loss…In the same noise field, you can wear the DANR DHP(C) for2.5 hours!
36Distribution NumbersSince 2007, Aegisound has been delivering a number of new products to the Navy for maintainer hearing protection and communications6,000 CTE30X custom earplugs4,000 foam and earseal upgrade kits1,200 MAX40 double hearing protectors50,000+ DC2 hearing protectors (1,000’s more on order)1,020 Argonaut® DHP Communication systems (1,000’s more on order)10’s of thousands of spare and replacement items deliveredSince 2009, Aegisound has been delivering several new products to Lockheed Martin for F-35 maintainer hearing protection and communications600 DANR DHP (non-comm) kits sold and delivered to LM200 DANR DHPC (comm enabled) kits sold and delivered to LMAegisound has several new products that are currently available that will further enhance protection, safety, and productivity for maintainers
37Products Currently Available for the Naval Aviators and Aircrew
38Aircrew Hearing Protection CEP with foam and custom earplugs Discuss hearing protection with communication options for the pilot and aircrew. This slide discuss the CEP (now referred to as the Mini-CEP).Comm Goes Both Ways -- When you think about radio comm quality, you need to think in terms of "the talker" and "the listener." Noise getting into the comm system at either or both ends, coupled with any hearing loss at either or both ends, increases the chance for missed calls, misinterpretations, and mishaps. Anything that can be done to reduce or block undesirable noise from getting into the comm system and to protect against hearing loss will make Naval Aviation that much safer and efficient.The addition of earplugs under helmet earcups decreases the ability to communicate since the earplugs attenuate speech signals from the earcup earphones at the same time as they attenuate undesirable noises coming in from outside the earcups. A new earplug is now available to help fix this problem.Mini-CEP Reduces Undesirable Noise while Channeling Thru Speech SoundsLogistics Tail The Mini-CEP requires no aircraft modification. Mini-CEPs are integrated into the existing rotary and fixed wing helmets and add <1oz. to the helmet. The Mini-CEP mod kits cost about $120 each and include assorted earplug sizes and fitting instructions. Training manuals and videos are also available. The Mini-CEP comm is wired in parallel with the existing helmet communication system, which continues to work even if the Mini-CEP fails.For more information contact CEP at:Communications & Ear Protection, Inc. :For price information, contact CEP, Inc. atHGU-68/PNavy Fixed Wing Helmet withVENTED CEPHGU-84/PNavy Rotary Wing Helmet withNOT VENTED CEP
39Oregon Aero Softseal ear cushions for use with the HGU-84 Product Name:Softseal Ear CushionsManufacture:Oregon AeroFeatures:Better hearing protection than stock ear cushion.More comfortable than plastic stock ear cushion.
40Aircrew Hearing Protection David Clark with active noise attenuation
41Products in Development for Naval Aviators and Aircrew
43Earplug Pressure Equalization During Flight Dr Earplug Pressure Equalization During Flight Dr. Talcott, NAVAIR 2014 SAFE conference2014Introduction: The Navy currently requires fixed wing aircraft pilots and aircrew to use vented earplugs to reduce the risk of otitic barotrauma; however vents may significantly reduce earplug noise attenuation, leading to increased risk of noise-induced hearing damage. The objective of this study was to determine the need for a venting requirement through the evaluation of pressure equalization capabilities of earplugs used by pilots and aircrew.Methods: Pressure equalization of 14 earplugs: vented and non-vented custom-molded earplugs, vented and non-vented Communications Earplugs (CEPs) with foam and custom-molded eartips (CEP402-C05, CEP505-C11, CEP505-C11-V, and CEP508-C15), vented and non-vented Attenuating Custom Communications Earpiece System (ACCESR) earplugs, Sound GuardT foam earplugs, and QuattroT Quad-flange earplugs were compared to that of the open ear during simulated flight profiles. Earplugs were evaluated using a custom ear canal simulator test rig in a small unmanned altitude chamber. Rate of ascent and descent, maximum altitude, and hold time at altitude were additional independent variables.Results: Analysis shows that of the earplugs evaluated; only the QuattroT produced enough pressure differential to potentially cause otitic barotrauma. These failures to equalize pressure did not occur on every trial and were observed for multiple flight profiles. When failure to equalize did occur, it tended to be present on both ascent and descent. There were small changes in pressure observed for some of the other earplugs, including CEPs with foam eartips. It is unclear if these pressure changes were due to failure to equalize or drifts in sensor readings.Discussion: Results suggest that QuattroT quad-flange earplugs should not be used during tactical jet flight due to their potential to prevent pressure equalization in the ear canal. More testing should be done to evaluate their suitability for other applications, such as rotary aircraft flight. Results do not support the need to vent communications earplugs for use in fixed wing aircraft.
44Aircrew Hearing Protection CEP with custom ear HGU-68/PNavy Fixed Wing Helmet withVENTED CEP(*not yet approved for flight)HGU-84/PNavy Rotary Wing Helmet withNOT VENTED CEP(approved for flight)
46Background: In-Ear Dosimetry There are multiple methods of calculating total daily exposure (TDE) for the purpose of real time administrative controls and personnel management in high noise environments. Three methods are considered: 1. Device NRR performance values with any associated regulatory de-rating guidance 2. Personal Attenuation Ratings (PAR) with known external noise fields 3. Real time in-ear noise measurement for continuous calculation of dose.
52Navy Audiology Specialty Leader Update Hearing injury rates have declined to 11.5%.Navy compliance (85.8%) has met target (85%) compliance threshold. USMC compliance (63.2%) is below target compliance threshold.The percentage of the Navy and USMC population with normal hearing has increased from 71% in 2001 to 82% in 2013.