Anechoic measurements of particle-velocity probes compared to pressure gradient and pressure microphones

• Autorzy: Woszczyk W. , Iwaki M. , Sugimoto T. , Ono K. , de Bree H. E.
• Języki publikacji: EN

Abstrakty

EN

The Microflown is an acoustic particle velocity sensor invented at the University of Twente in Holland in 1994 and commercialized in 1997 [1, 9]. The sensor directly measures particle velocity rather than pressure-gradient as do most unidirectional and bidirectional microphones. The sensor has several interesting operational characteristics however few measurements of the Microflown have been published until now making it difficult for a potential user to assess the merits of this transducer in comparison to high quality condenser microphones commonly used in music and speech recording. This paper offers some insight by presenting anechoic measurements of particle velocity probes compared to the measurements of pressuregradient and pressure microphones (of condenser type) made under identical acoustical conditions at varying distances from a point source having a wide frequency range. Detailed frequency response measurements show how the characteristics of these transducer types are dependent on their distance to the source, and highlight the need of transducer calibration with respect to distance. Very few microphone manufacturers publish frequency response data for more than one reference distance to the source although distance is often used to modify the applied response of the microphone. An additional goal for making these measurements is to establish the relationship between particle velocity and pressure gradient values using the same acoustical conditions. The measurements were made in the large anechoic chamber of the NHK Science and Technical Research Laboratories (STRL) in Tokyo during the April-May of 2006.

Słowa kluczowe

EN

microphone measurements; anechoic microphone response; Microflown sensor; particle velocity; pressure gradient; pressure transducer; proximity effect; distance dependent measurement; small acoustic source

• Wydawca: Instytut Podstawowych Problemów Techniki PAN ; Komitet Akustyki PAN ; Polskie Towarzystwo Akustyczne
• Czasopismo: Archives of Acoustics
• Rocznik: 2007
• Tom: Vol. 32, No. 3
• Strony: 643--658
• Opis fizyczny: Bibliogr. 10 poz., rys.

Twórcy

autor

Woszczyk W.

• McGill University Schulich School of Music Department of Sound Recording, Montreal, QC, Canada

autor

Iwaki M.

• NHK Science & Technical Research Laboratories 1-10-11 Kinuta, Setagaya-ku, Tokyo, 157-8510, Japan

autor

Sugimoto T.

• NHK Science & Technical Research Laboratories 1-10-11 Kinuta, Setagaya-ku, Tokyo, 157-8510, Japan

autor

Ono K.

• NHK Science & Technical Research Laboratories 1-10-11 Kinuta, Setagaya-ku, Tokyo, 157-8510, Japan

autor

de Bree H. E.

• Microflown Technologies PO Box 300 – 6900 AH Zevenaar, The Netherlands

Bibliografia

• [1] DRUYVESTEYN W. F., DE BREE H.-F., ELWENSPOEK M., A new acoustic measurement probe; The Microflown, IOA, 1999 London (www.microflown.com).
• [2] DRUYVESTEYN W. F., DE BREE H.-F., RAANGS R., A low-cost intensity probe, J. Audio Eng. Soc., 51, 344–357 (2003).
• [3] DE BREE H.-F., LANOYE R., DE COCK S., VAN HECK J., In situ, broad band method to determine the normal and oblique reflection coefficient of acoustic materials, Noise and Vibration Control 05NVC-152, Copyright 2004 SAE International.
• [4] DE BREE H.-F., RAANGS R., DRUYVESTEYN W. F., Sound intensity measurements with the Microflown sensor, Inter-Noise 2004, The 33rd International Congress and Exposition on Noise Control Engineering, August 22–25, 2004, Prague, Czech Republic 2004.
• [5] JACOBSEN F., LIU Y., Near field acoustic holography based on an array of particle velocity sensors, Inter-Noise Rio 2005, The 2005 Congress and Exposition on Noise Control Engineering, 7-10 August 2005, Rio de Janeiro, Brazil 2005.
• [6] JACOBSEN F., DE BREE H.-F., A comparison of two different sound intensity measurement principles, J. Acoust. Soc. Am., 118, 3, Pt. 1, 1510–1517 (2005).
• [7] JACOBSEN F., DE BREE H.-F., Measurement of sound intensity: p-u probes versus p-p probes, Proceedings of NOVEM 2005, Saint Raphaël, France 2005.
• [8] WOSZCZYK W., Low-latency virtual acoustics for live music performance and recording, CD-ROM Proceedings of the Thirteenth International Congress on Sound and Vibration (ICSV13), July 2–6, 2006, Vienna, Austria, Eberhardsteiner J., Mang H. A., Waubke H. [Eds.], Publisher: Vienna University of Technology, Austria, ISBN: 3-9501554-5-7.
• [9] DE BREE H.-F., LAMMERINK, ELWENSPOEK, FLUITMAN, Use of a fluid flow measuring device as a microphone and system comprising such a microphone, Patent PCT/NL95/00220, 1995.
• [10] DE BREE H.-F., Add-on Microflown for a High-End Pressure Gradient Microphone, AES Convention Paper, No. 5181, Presented at the 109-th Convention of Audio Engineering Society in Los Angeles, September 22–25, California, U.S.A. 2000.