Acoustic characterisation of boards manufactured with fruit stones mixed with coconut fibre

Sustainable and recycled materials are being used in a wide range of fields to solve a waste management problem and, at the same time, to confer them a second life. These materials include fruit stones of different crops: apricot, peach, cherry and olive. Employing fruit stones as acoustic materials contributes to minimise the environmental impact and to create a new product with interesting sound-absorption properties, apart from offering aesthetic added value. Some previous works have demonstrated the application of fruit stones panels as sound absorbers. This study aims to determine the acoustic properties of boards manufactured with a mixture of the four above fruit stone types. A coconut fibre layer is added to compare the results with and without coconut fibre. The experimental results show that acoustic properties improve by increasing board thickness and the sound-absorption coefficient is higher when a coconut fibre layer is added. Sound transmission loss is not significantly affected by adding the coconut fibre layer.