Selection of Hearing Protectors IRISH DEFENCE FORCES Comdt Colin Roche

1. Selection of Hearing Protectors IRISH DEFENCE FORCES Comdt Colin Roche

2. Structure Defence Forces

3. Noise Challenges Irish Defence Forces

4. Noise sources in Defence Forces can be generally categorised, Impulse Noise Weapon Noise Continuous (Occupational) Noise Army Air Corps Navy Noise Challenges

5. Naval Operations Ships main armament - Impulse Ships Engine Room – Continuous Technicians Hearing Protectors – Muffs – Peltor Optime III Naval Service

6. Aircraft Operations Aircraft Engine Noise - Continuous Technicians Ramp Hearing Protectors – Muffs – Peltor Optime III Pilots and Air Crew Aircraft Cabin Hearing Protectors – Plugs – E.A.R. Workshop Noise - Continuous Air Corps

7. Army • Occupational Noise Sources • Workshops • Printing Press • Bands

8. Weapons Noise – Impulse All weapons in use generate noise levels exceeding the Exposure Limit 140 dB(C) Defence Forces Noise Challenge

9. Defence Forces Noise Challenge • Challenge • How to protect the solider and still allow for Command & Control • Hearing protectors are not rated for impulse noise • Compatible with other Personal Protective Equipment

10. Operational Weapon Environment Hearing protector solutions Passive Muff (Bullseye I) Plug Weapon Noise

11. Weapon Noise • Electronic (active) • Muff (ComTac XP) Outside Mic Internal Speaker

12. Hearing Protectors worn Single (Plugs or Muffs) or Double Protection (Both Plugs and Muffs) Single Small arms (pistols and rifles) Double Crew served weapons (anti armor, artillery and mortar) Single or Double

13. Must provide sufficient protection Fit under the soldiers helmet Hearing Protectors Requirements

14. Choice of Plug Solid plug Once fitted correctly into the ear canal provides instant protection The squashable type plug for gun noise was deemed unsuitable, due to the time delay in forming seal in ear canal and; concern about hygiene

15. Challenge Command & Control Hearing Protectors not only screen out unwanted noise but also things needed to be heard Soldiers need to hear commands and Officers and NCOs need to be heard in order to maintain control This is one of the main barriers to soldiers wearing hearing protection continually

16. SolutionSmall Arms Passive hearing protection is suitable where soldiers are firing personal weapons at fixed targets. The practice is predictable and the soldiers are briefed on what is expected of them Control is relatively easy as there is minimum movement

17. ChallengeCrew Served Weapons Communication is required between soldiers on a crew served weapon In this case passive hearing protection hinders the air communication between the crew This has a detrimental effect on command and control Resulting is the desire to remove wear hearing protection

18. SolutionCrew Served Weapons Active electronic muffs allows for air communication between the crew members This has greatly increased the incidence of wearing the hearing protection continually

20. ChallengePatrolling Maintaining communication between soldiers on patrol and working away from each other Command and Control paramount With passive muffs or plugs effectiveness and ability to communicate reduced Resulting in Situation Awareness reduced, Soldier feels isolated and more vulnerable

21. SolutionPatrolling Active muffs allow for air communication Soldiers able to hear and react to commands and instructions Situation awareness maintained Soldiers able to deal with anxiety better because feeling of isolation reduced Surprise Effect - Psychological Stress reduced

23. Testing for Impulse Noise • Bruel and Kjaer • Artificial Test Fixture • Head and Torso Simulator (HATS)