Abstract

SEPULVEDA D, Hernán D  and  MACIA M, Carlos A. Experimental methodology for obtaining sound absorption coefficients. Rev. Fac. Nac. Salud Pública [online]. 2011, vol.29, n.2, pp.128-138. ISSN 0120-386X.

OBJECTIVE: a new methodology designed to obtain sound absorption coefficients using genetic algorithms is proposed. METHODOLOGY: sound waves are generated and conducted along a rectangular silencer and attenuated by the absorbing material covering its walls. Taking the sound pressure level related to attenuation, a search is developed to find parameters of the proposed attenuation expressions including geometric factors, wavelength and absorption coefficient. RESULTS: a variety of adjusted mathematical models were found capable of estimating the absorption coefficients based on the characteristics of a rectangular silencer used to measure attenuation. CONCLUSIONS: this methodology allows to obtain in a simple and low-cost way absorption coefficients for new materials, provided it may slightly differ from those obtained by means of other methods, but admitting that it can also provide solutions within a certain range of accuracy in applied engineering for the design of noise control systems.

Keywords : noise; sound absorption coefficient; attenuation; genetic algorithms.

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