Sound Power and Sound Energy Measurements Using an Ellipsoidal Measurement Surface

Details

• Personal Author:
  Zechmann, Edward L.
• Description:
  To support purchasing low noise products, sound power and sound energy measurements of sufficient quality need to be routinely made by consumers on a global scale. Sound power measurements using ISO 3744, 3745, and 3746 are conducted in a free field using an acoustic far-field approximation of the intensity integrated over an enveloping measurement surface. Sound power and sound energy measurements generally use a hemispherical, parallelepiped, or cylindrical measurement surface. Those measurement surfaces have limitations and assume that the measurement points lie on the measurement surface often in preferred positions. An alternative approach is to choose microphone positions that optimally satisfy the assumptions of the measurement. The measurement surface should then be fit to the chosen microphone positions. Regression methodologies are available for fitting ellipsoids. The number of microphone positions can be as few as three to fit an ellipsoid. An ellipsoidal measurement surfaces can abut zero, one, two, or three orthogonal reflecting planes. Correction equations for the microphone locations and the angle errors for the microphone orientation and wave propagation direction are shown. This paper will present simulations of sound power, sound energy, and corrections for environmental reflections for ISO 3745 and other measurement surfaces. [Description provided by NIOSH]
• Subjects:
  Engineering Environmental Exposure Hearing Hearing Loss Noise Noise, Occupational Occupational Health Risk Assessment Risk Factors Safety Workplace

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• Keywords:
  Acoustic Measurement Exposure Levels Hearing Conservation Hearing Loss Prevention Hearing Protection Humans Measurement Equipment Noise Control Noise Exposure Noise Levels Noise Measurement Risk Factors Sound Sound Attenuation Sound Propagation Work Environment Workers

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• Publisher:
  Institute of Noise Control Engineering
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  District of Columbia ; Ohio ; OSHA Region 3 ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DFSE - Division of Field Studies and Engineering
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  14
• NIOSHTIC Number:
  nn:20063875
• Citation:
  Abstracts from the Inter-Noise 2021 Proceedings: Next 50 Years of Noise Control, the 50th International Congress and Exposition on Noise Control Engineering, August 1-5, 2021, virtual event. Washington, DC: Institute of Noise Control Engineering, 2021 Aug; :14
• Federal Fiscal Year:
  2021
• Peer Reviewed:
  False
• Source Full Name:
  Abstracts from the Inter-Noise 2021 Proceedings: Next 50 Years of Noise Control, the 50th International Congress and Exposition on Noise Control Engineering, August 1-5, 2021, virtual event
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:c7611a6089d87ff43d7e9244a4367bce12703152693648c7e343b04490bbc6c87dd5e9efb6b831c92557832b9800446a5c418fccdeb92f8f841f08121d08e593
• Download URL:
  https://stacks.cdc.gov/view/cdc/222418/cdc_222418_DS1.pdf
• File Type:
  [PDF - 166.81 KB ]