The use of calabashes as sound absorption alternative material

Abstract

This paper aims to give some scientific information on calabashes used as sound absorption alternative material. For two decades the need for concert halls with adequate acoustic quality has been increasing in Brazil. Therefore, modern buildings have been built in our country according to adequate standers. Nevertheless, the cost of the necessary acoustic materials in current use is prohibitive. In order to reduce building budgets, researches have been done by the acoustic lab from UFSM since 1986. The present research aims to find out whether residue material derived from calabash industries in our state can work properly as sound absorbent material at a low cost. The evaluation of the sound absorption coefficient for these materials was obtained using sound measuring equipment employing the frequency range from 100 Hz to 4.000 Hz. In order to get the best performance, the material was installed in at least eleven ways and a math model was used to describe the phenomenon. The obtained results indicated that the researched material behaved as Helmholtz resonator. This research has provided scientific information on how calabash residue cab be used as a sound absorption alternative material.