A BRIEF REVIEW OF RECENT TECHNIQUES FOR ESTIMATION OF SOUND ABSORPTION COEFFICIENT WITH THE USE OF SOUND INTENSITY

Acoustic prediction and modelling of acoustic designs is mostly dependent on the acoustic performance of its materials. In architectural acoustics, one of the most significant properties is that of the absorption. This project presents a short review of recent techniques which aim to determine the sound absorption coefficient of acoustic materials in situ, laboratory or computationally with the use of sound intensity probes. These probes provide clear information on the direction of sound wave propagation and recently, with the invention of the Microflown sensor a direct measurement of particle velocity became possible. Therefore intensity based techniques have been suggested to establish new methods for further precise acoustic measurements. This paper presents the development of some alternative techniques over the last 15 years that deal with ununiformed laboratory conditions, frequency range and sample size limitations and the absence of standardized in situ methods. A historical review of that work is of great interest, assists the comparison, evaluations and consolidation of the existing techniques and makes the existing framework more clear for the suggestion of even more efficient techniques.