Absorption properties of olive pruning residues (OPR): Acoustic measurements using impedance tube and reverberant chamber

The growing demand for sustainable construction materials has stimulated interest in the development of bio-based alternatives to conventional acoustic absorbers. This study investigates the sound absorption performance of olive tree pruning residues (OPR), including leaves and small branches. Acoustic measurements were conducted using both impedance tube and reverberant chamber methodologies on a range of sample configurations, including fresh leaves, dried leaves, shredded branches and hydroponic composites obtained by combining dried olive leaves with wheat cultivation. The results demonstrate that OPR exhibit good sound absorption properties, particularly at medium and high frequencies. The hydroponic composites provided additional structural stability while maintaining favourable absorption characteristics. Although further research is required to evaluate fire resistance, durability, mechanical performance and large-scale manufacturing feasibility, this study contributes to the growing body of knowledge on bio-based acoustic materials and highlights the potential of agricultural residues as environmentally responsible alternatives to conventional sound absorbers.