Original article

Acoustic quality of vène wood (Pterocarpus erinaceus Poir.) for xylophone instrument manufacture in Mali

¹ AgroParisTech/ENGREF, 14, rue Girardet, 54 042 Nancy, France
² CIRAD (Centre de coopération internationale en recherche agronomique pour le développement), Production et valorisation des bois tropicaux, Montpellier, France
³ CRB (Centre de Recherche sur le Bois), Département des sciences du bois et de la forêt, Pavillon Gene H. Kruger, local 2367, Université Laval, Québec, Canada

^* Corresponding author: loic.brancheriau@cirad.fr

Received: 14 January 2010
Accepted: 6 March 2010

Abstract

• Vène wood (Pterocarpus erinaceus Poir.) is currently the favorite wood for manufacture of xylophone in Mali. A dynamic analysis method with free boundary conditions, known as BING, was used to determine the main acoustic properties: specific dynamic modulus (E_L/ρ), damping coefficient or internal friction (tan δ), sound radiation coefficient (SRC) and peak response (PR).

• The aim was to investigate the acoustic properties of vène wood (1) along three radial locations (internal: IHW, median: MHW, external: EHW); (2) related to two geographic origins (Guinean and Soudanian areas); and (3) to investigate the effect of ring width (RW), basic density (D_b) and extractive content (EC) on these properties.

• High correlations were shown between tanδ with E_L/ρ and EC. tanδ decrease with increasing E_L/ρ or EC. No significant difference of SRC was found between the geographic areas and the radial locations. No correlation between RW and acoustic properties was observed. E_L, E_L/ρ and PR were significantly higher for wood from the Guinean area than from the Soudanian area and also higher for EHW and MHW than for IHW. tanδ follows inverse trends. These results could explain why the Malian xylophone makers empirically use only the wood from EHW and MHW.