ONLINE ISSN 2069-7430 ISSN-L 1841-4737 PRO LIGNO Vol. 15 N° 3 2019 www.proligno.ro pp. 34-44 34 SELECTED ACOUSTIC PROPERTIES OF Aningeria robusta (A.CHEV) WOOD IN RELATION TO FIBRE AND PHYSICO-MECHANICAL PROPERTIES Kayode OLAOYE Federal College of Forestry, Forestry Research Institute of Nigeria, Nigeria E-mail: olaoye.ko@frin.gov.ng Funke ADEBAWO Federal College of Forestry, Forestry Research Institute of Nigeria, Nigeria Abstract: The composition of wood makes wood a unique material for musical instrument and other acoustic applications. However, fibre properties, physical and mechanical properties has been highlighted to influence acoustic performance of wood. Notwithstanding, insufficient information about interaction between these properties has hindered the efficient utilization of lesser used wood species for acoustic purposes. This work thus endeavoured to study the existing relationship between fibre, physico-mechanical and selected acoustic properties of Aningeria robusta wood. Three trees of A. robusta were were fell for the fibre, physico- mechanical and acoustic tests. The tests were carried out according to standard procedures. Mean fibre length, fibre diameter, lumen width and cell wall thickness were 1.54±0.05mm, 11.71±0.19μm, 8.79±0.41μm, 1.46±0.29μm respectively. Moisture content, wood density, MOR, and MOE were 55.54±2.98%, 0.43±0.18g/cm 3 , 123.91±4.74N/mm 2 , 5876.89±382.82N/mm 2 , while Speed of sound, specific elastic modulus, sound radiation coefficient, and acoustic impedance were 3711.46±183.35m/s, 14.06±0.70 (GPa), 8.90±0.39, 1.6 x 10 6 ±47017.33kg/m 2 s respectively. Correlation analysis was positively significant for MOE and acoustic properties. Wood density also had a negative significant correlation with acoustic properties except for acoustic impedance. The findings of this study reveals that relationship existed between these properties. However, it can be species dependent. Key words: Correlation, Relation, Fibre, Physico-mechanical, Acoustic. INTRODUCTION The composition of wood makes wood to be an outstanding material; it is versatile, inexhaustible and renewable. Wood can produce sound by direct striking, and can amplify or absorb sound waves originating from other bodies. For these reasons, it is a unique material for musical instrument and other acoustic applications. Also, some wood are acoustic in nature and has the ability to produce sound effect. Because of this unique property, wood is used in producing a number of musical instruments such as guitar, violin, piano, xylophone and percussion. However, physical and mechanical properties has been highlighted to influence acoustic performance of wood. For instance, Tsoumis (1991) reported that the pitch of sound produced depends on the frequency of vibration, which can be affected by the dimensions, density, moisture content, and modulus of elasticity of the wood thus stating that smaller dimensions, lower moisture content, and higher density and elasticity produce sounds of higher pitch. Also, George, (2014) stated that the velocity of sound in wood is reduced by moisture, thus contributes to faster damping of sound in wood. Of the lesser used wood species (LUWS) in Nigeria, Aningeria robusta is fast becoming popular due to its excellent performance in structural applications especially in roofing, and in recent times, door frames and furniture. Aningeria robusta belongs to the family Sapotaceae, a hardwood. It is referred to as ‘agengre’ in Cote d’Ivoire, ‘landosan’ in Nigeria and ‘osan’ in Uganda (TRADA 1979; Ajala and Ogunsanwo 2011), ‘mukali’ in Angola, ‘mukangu’ in Kenya (Chudnoff 1980; Ajala and Ogunsanwo 2011) and ‘asafonia’ in Ghana (Okai 2003). However, an important research area of wood utilization which has not found enough concentration and popularity is the acoustic. Whereas, the potential utility of any wood is dependent upon its basic anatomical, physical and mechanical properties. These properties are the underlying factors determining the behaviour and recommendation of wood for general and peculiar uses (FAO 1998). Similarly, Poku et al. (2001) stated that maximum utilization of lesser used wood species in the timber market requires technical information that relates to utilization of the species. Therefore, the successful utilization of A.robusta for acoustic purposes also requires technical information of its anatomical, physical and mechanical properties in relation to its acoustic properties. Thus, there is need to study the anatomical, physical and mechanical properties in relation to the acoustic properties of A.robusta wood.