Accession Number:

AD0656938

Title:

DEVELOPMENT OF AUDIO TRANSDUCER HELMET ASSEMBLY.

Descriptive Note:

Quarterly rept. no. 1, 2 Jan-31 Mar 67,

Corporate Author:

CBS LABS STAMFORD CONN

Personal Author(s):

• Rosenheck,Allan J.
• DiMattia,Alfred L.

Report Date:

1967-07-01

Pagination or Media Count:

23.0

Abstract:

Program objective is the development of an Audio Transducer Helmet Assembly to be used in the Army Aircrewman Helmet. The assembly includes earphones mounted in attenuating earcups along with auxiliary hardware, wiring and ancillary devices. A further goal is development of a miniature moving-coil, noise-cancelling microphone having improved noise-cancellation characteristics. A comprehensive review of previous efforts was performed including evaluation of the enclosure presently used on the APH-5 helmet and a survey of several novel ear enclosure concepts under recent Army contracts--low-frequency-coupled volumes, low-profile ear enclosures, gel-filled cushions, mutual-stiffness-coupled and bellows-coupled enclosures. Evaluation and comparison of these and other methods revealed that low-frequency-coupled volumes or low-profile enclosures, in conjunction with gel-filled cushions, are most feasible for this application. Assessment was made of the space available in the present helmet for enclosures with a goal of avoiding an increase in the external ear-to-ear measurement. Various techniques of mounting the enclosures within the helmet were explored and experiments performed toward optimizing the gel-filled cushion design. Author

Descriptors:

• *EARPHONES
• HELMETS
• FLIGHT CREWS
• MICROPHONES
• EAR PROTECTORS
• ACOUSTIC INSULATION
• TRANSDUCERS

Subject Categories:

• Electrical and Electronic Equipment
• Protective Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE