Experimental Study of Sound Absorption Coefficients of Common Interior Finishing Materials in Jos

Interior finishing materials significantly influence the acoustic performance of rooms by controlling sound absorption, reflectivity, and reverberation. This study experimentally determines the sound absorption coefficients of six commonly used interior materials in Nigerian buildings, including plain concrete, painted concrete, carpet tiles, PVC floor tiles, plasterboard, and louvered window glass, using a standing wave tube apparatus built in the Physics Department workshop at the University of Jos, Plateau State, North Central Nigeria. Absorption coefficients were measured at octave band center frequencies from 125 Hz to 4000 Hz following the ISO 10534-2 standard impedance tube method. Each material sample was tested at three independent positions within the tube to account for spatial variability, and results were averaged. The absorption coefficient of carpet tiles averaged 0.38 at 1000 Hz, substantially higher than PVC tiles at 0.06 at the same frequency, indicating superior acoustic damping performance. Plasterboard showed frequency-dependent behavior with peak absorption at 250 Hz. The study cross-validates some measurements against literature data for similar materials tested internationally and discusses reasons for observed deviations linked to locally sourced material composition. A practical acoustic design chart is developed for use by Nigerian building designers when specifying interior materials for acoustically sensitive spaces such as offices, studios, and lecture halls. Keywords: sound absorption, acoustic coefficient, interior materials, Jos, standing wave tube