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http://dx.doi.org/10.7776/ASK.2021.40.3.254

Method of deriving the acoustic impedance and sound absorption coefficient of materials by manipulating electrical impedance of a loudspeaker  

Doo, Sejin (Decoton Inc.)
Publication Information
The Journal of the Acoustical Society of Korea / v.40, no.3, 2021 , pp. 254-260 More about this Journal
Abstract
When measuring the sound absorption coefficient of a specimen, a reverberation room which is costly or an impedance tube which has limitations in measuring low frequencies have been engaged. In this paper, a new measurement method of acoustic impedance or sound absorption coefficient has been suggested, which does not need microphones and only uses electrical impedance measurement data and derived Thiele/Small parameters of a speaker. The theory of this method has been described using equivalent circuit of the loudspeaker and acoustic properties of a test specimen are measured to demonstrate the validity of this method. It was confirmed that this method can easily measure the sound absorption coefficient in the low frequency band, which was previously difficult to trust. The advantages, limitations, and applicability of this method are discussed.
Keywords
Sound absorption; Acoustic impedance; Speaker; Equivalent circuit; Measurement;
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