Reduction of Sound in Diving Helmets

Abstract

Analysis of the sound within a standard diver's helmet shows a preponderance of high pitched components which tend to mask the s, c, d and t elements of speech to such an extent that voice communication between diver and tender is rendered difficult and at times practically impossible. The main source of this intense noise background has been traced to the hand operated air inlet valve. Through redesign of this valve and the installation of a low pass acoustical filter across the air intake, the intensity of the masking noise background has been reduced about 30 db. This permits fairly satisfactory intercommunication when the standard power telephone system is used and should allow practically perfect communication when the diver uses an inertia or throat type of microphone and head helmet-mounted earphones.

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Document Details

Document Type
Technical Report
Publication Date
Jun 07, 1939
Accession Number
AD1158820

Entities

People

  • F. W. Struthers

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Flow
  • Air Intakes
  • Ambient Noise
  • Check Valves
  • Earphones
  • Engineering
  • Frequency
  • Intensity
  • Low Density
  • Microphones
  • Noise
  • Standards
  • Systems Engineering
  • Telephone Systems
  • Valves
  • Voice Communications

Readers

  • Acoustics.
  • Human-Computer Interaction (HCI).
  • Materials Science