MIL-PRF-87819 Headset-Microphone, \(Hearing Protective Type, High And Moderate Ambient Noise Levels\), General Specification ForThis specification covers the requirements for headset-microphone with rigid headband. These parts meet established requirements for communications equipment used to protect against hazardous noise exposure, and are approved for use in certain high and moderate ambient noise level applications \(see 6.1\). The term headset is to be used interchangeably for headset-microphone and is used when referring to any of the articles covered in this specification.

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MIL-PRF-87819B

3.4.6 Rigid materials. The materials used shall be of sufficient durability and hardness to provide the

required strength and rigidity with maximum strength to weight ratio. Any metals shall be of a corrosion

resistant type.

3.4.7 Earcup shells. The earcup shall conform to the overall dimensional envelope on figure 1, in order

to avoid obstructions to the emergency oxygen mask harness. The earcup shell material shall resist

breakages at the yoke attachment, at the seams (if any), and at points where cable and volume control

holes have been drilled, when tested in accordance with 4.7.6. Treatments used to process the device

shall not cause skin irritation.

3.4.8 Earcup fillers. If the earcup is supplied with a filler material, it shall be flame retardant, and meet

the environmental requirements (see 3.5.5, 3.5.6, 3.5.8, 3.5.9, 3.5.10, and 3.5.15) of this specification. It

shall not obstruct the auditory path of the transducer, and shall only be permanently attached to the

earphone element if the manufacturer demonstrates that such attachment increases the signal-to-noise

ratio of the headset. Fillers shall allow clearance of at least 0.750 inch, from the uncompressed face of

the earcushion, unless otherwise specified (see 3.1).

3.4.8.1 Earcup shell cushion (earcushion). The earcup shall be supplied with a cushion, meeting the

human interface dimensional requirements of Air Force drawing 9312801. It shall be replaceable without

causing damage to the earcup. As specified in ASTM D3574, the cushion shall have a filler material that

meets the noise-attenuation requirements of this specification and has a density that supports the comfort

requirements of the headset's intended use, not less than 5.7 lbs/ft . The fillers and cushion surface

material shall be flame-retardant and shall not crack, tear, or otherwise degrade under the environmental

conditions of this specification (see 3.5.5, 3.5.6, 3.5.8, 3.5.9, 3.5.10, 3.5.15). The color shall be black.

The fillers shall not leak, in the event of puncture to the cushion surface.

3.4.8.2 Microphone protective shell cushion. The microphone protective shell cushion shall be as

specified, when required (see 3.1).