Quantitative analysis of sound absorption properties of plants in indoor environment for enabling sustainable practices

This paper showcases the results of the sound attenuation properties of some plants with a soil substrate for use as green sound absorbers in an indoor space. The plants used in this experiment were needed to survive in an indoor environment, hence only tropical, thermophilic plants which could grow in high humidity and warm temperatures with indirect sunlight were selected. An impedance tube of 100 mm dia. was used to calculate the direct incidence acoustic absorption coefficient of the plants and larger samples were tested within a reverberation chamber. The soil substrate used was a high porosity and low-density sample of perlite and coconut fibres. The results show that ferns and baby tears were good absorbers along with the soil substrate, whereas begonia was a better absorber at the lower and higher frequencies. The decibel drop by the fern with soil substrate is the highest with a decrease of frequency and the lowest is by Green Ivy which is due to morphological conditions.