A new approach to the measurement of very low acoustic noise levels

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Abstract

Measurements of very low acoustic noise levels are, in general, limited by the noise voltage of the input stage of the amplifier, and with condenser microphones a further limitation is the self-noise of the microphone capsule resulting from the acoustic resistance which damps the microphone diaphragm.

The method of measurement described is an application of the principle of energy addition. The total noise from the system is integrated over a suitable time interval firstly with the microphone shielded from the acoustic noise to be measured, and then with it exposed. Noise signals of up to 15 dB below the system noise level can readily be determined.

References (9)

  • L.S. Whittle

    A determination of the normal threshold of hearing by bone conduction

    Journal of Sound and Vibration

    (1965)
  • ASA

    American Standard Criteria for Background Noise in Audiometer Rooms

    (1960)
  • J.J.Zaalberg van Zelst

    Circuit for condenser microphones with low noise level

    Philips Technical Review

    (1947)
  • P.J. Baxandall

    New low-noise transistor circuit for electrostatic microphones

    Wireless World

    (1963)
    P.J. Baxandall

    New low-noise transistor circuit for electrostatic microphones

    Wireless World

    (1963)
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