Archives of Acoustics, 37, 2, pp. 219–225, 2012

Numerical Compensation of Air Absorption of Sound in Scale Model Measurements

Dejan G. ĆIRIĆ
Faculty of Electronic Engineering, University of Nis

Aleksandar PANTIĆ
Knauf Insulation d.o.o Belgrade

The absorption of sound in air represents one of the main problems of the scale model measurements.
This absorption, especially at higher frequencies, is considerably greater than the value determined by
the law of acoustical similarity between the full scale and the scale model. Different alternatives are
applied for compensation of the excess air absorption including a numerical compensation. In this paper,
a modified approach to numerical compensation is proposed. It is based on compensation of the sound
decay only, and not background noise. As a consequence, there is no an increase of background noise in
the compensated impulse response. The results obtained by the proposed procedure are compared to the
corresponding ones obtained by the other procedures.
Keywords: acoustic measurement; scale model; air absorption; numerical compensation
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