Study of sound absorption of Azov Sea green and brown algae and starch composites

Abstract

Poor acoustic conditions in educational and working environments negatively affect cognitive performance, learning efficiency, and overall well-being, prompting the search for effective solutions to reduce noise and reverberation. One possible solution is the use of sound-absorbing panels made from natural materials. Although a wide range of natural fibers is used in practice, the acoustic properties of algae have not yet been sufficiently investigated. This study examines the sound absorption of composites made from dried brown and green algae collected from the Sea of Azov and corn starch as a binder. The sound absorption coefficient was measured using an impedance tube in accordance with ISO 10534-2, within the frequency range of 160–5000 Hz. Samples with a thickness of 50 mm were prepared by varying the binder concentration (0–30%) and sample density (150, 200, and 300 kg/m³). The results showed that the average sound absorption coefficient ranged from 0.55 to 0.64, with the highest values obtained for samples with a density of 200 kg/m³ containing 10% and 30% corn starch. It was found that increasing the binder content shifts the sound absorption peak toward higher frequencies, while higher sample density improves sound absorption at low frequencies. The aim of this study is to evaluate the sound absorption properties of algae–starch composites and to determine optimal structural parameters for their application in sound-absorbing materials.

Article in Lithuanian