Sound quality assessment of wood for xylophone bars


Authors: Aramaki M., Bailleres H., Brancheriau L., Kronland-Martinet R., Ystad S.
Publication Date: April 2007
Journal: Journal of the Acoustical Society of America (JASA) (Vol 121(4), pp: 2407-2420, 2007)


Xylophone sounds produced by striking wooden bars with a mallet are strongly influenced by the mechanical properties of the wood species chosen by the xylophone maker. In this paper, we address the relationship between the sound quality based on the timbre attribute of impacted wooden bars and the physical parameters characterizing wood species. For this, a methodology is proposed that associates an analysis-synthesis process and a perceptual classification test. Sounds generated by impacting 59 wooden bars of different species but with the same geometry were recorded and classified by a renowned instrument maker. The sounds were further digitally processed and adjusted to the same pitch before being once again classified. The processing is based on a physical model ensuring the main characteristics of the wood are preserved during the sound transformation. Statistical analysis of both classifications showed the influence of the pitch in the xylophone maker judgement and pointed out the importance of two timbre descriptors: the frequency-dependent damping and the spectral bandwidth. These descriptors are linked with physical and anatomical characteristics of wood species, providing new clues in the choice of attractive wood species from a musical point of view.


Digital tuning of impact sounds


Original sounds can be modelled and tuned using analysis-synthesis processes. Two examples corresponding to frequency transpositions toward higher and lower frequencies are given below:


Coula edulis Baill. Faucherea parvifolia H.Lec.


Sounds used for the classification test C3 (sounds with identical pitches)


(photo credits: L. Brancheriau, P. Detienne and D. Guibal)


Botanical Name Country Image Sound
Pericopsis elata Van Meeuw Congo PericopsisElata_im_147
Scottellia klaineana Pierre Cote d’Ivoire ScottelliaKlaineana_im_028
Ongokea gore Pierre Congo OngokeaGore_im_148
Humbertia madagascariensis Lamk. Madagascar HumbertiaMadagascariensis_L
Ocotea rubra Mez Guyane Francaise OcoteaRubraMez_im_053
Khaya grandifoliola C.DC. Cote d’Ivoire KhayaGrandifoliola_im_136
Khaya senegalensis A.Juss. Burkina faso KhayaSenegalensis_im_180
Coula edulis Baill. Cameroun CoulaEdulis_im_197
Tarrietia javanica Bl. Cambodge TarrietaJavanica_im_101
Entandrophragma cylindricum Sprague Cote d’Ivoire EntandrophragmaCylindricum_
Afzelia pachyloba Harms Cameroun AfzeliaPachyloba_im_141
Swietenia macrophylla King Martinique SwieteniaMacrophyllaKing_im
Aucoumea klaineana Pierre Congo AucoumeaKlaineana_im_171
Humbertia madagascariensis Lamk. Madagascar HumbertiaMadagascariensis_L
Faucherea thouvenotii H.Lec. Madagascar FaucheraThouvenotii_LB
Ceiba pentandra Gaertn. Cote d’Ivoire CeibaPentandra_im_108
Letestua durissima H.Lec. Congo LetestuaDurissima_im_023
Monopetalanthus heitzii Pellegr. Gabon MonopetalanthusHeitzii_im_0
Commiphora sp Madagascar CommiphoraSp._LB
Dalbergia sp Madagascar DalbergiaSp._LB
Hymenolobium sp Guyane Francaise HymenolobiumSp._im_102
Pseudopiptadenia suaveolens (Miq.) Brenan Guyane Francaise PseudopiptadeniaSuaveolens_
Parkia nitida Miq. Guyane Francaise ParkiaNitida_im_111
Bagassa guianensis Aubl. Guyane Francaise BagassaGuianensis_im_065
Discoglypremna caloneura Prain Gabon DiscoglypremnaCaloneura_LB
Faucherea parvifolia H.Lec. Madagascar FaucheraThouvenotii_LB
Brachylaena ramiflora Humbert Madagascar BrachylaenaRamiflora_LB
Simarouba amara Aubl. Guyane Francaise SimaroubaAmara_im_093
Gossweilerodendron balsamiferum Harms Gabon GossweilerodendronBalsamife
Manilkara mabokeensis Aubrev. Centre Afrique ManilkaraSp._im_049
Shorea-rubro squamata Dyer Philippines ShoreaSquamata_LB
Autranella congolensis A.Chev. Centre Afrique AutranellaCongolensis_im_08
Entandrophragma angolense C.DC. Congo EntandrophragmaAngolense_im
Distemonanthus benthamianus Baill. Cameroun DistemonanthusBenthamianus_
Terminalia superba Engl. et Diels Cameroun TerminaliaSuperba_im_005
Nesogordonia papaverifera R.Cap. Cote d’Ivoire NesogordoniaPapaverifera_im
Albizia ferruginea Benth. Cote d’Ivoire AlbiziaFerruginea_im_001
Gymnostemon zaizou Aubrev. et Pellegr. Cote d’Ivoire GymnostemonZaizou_LB
Anthonotha fragrans Exell et Hillcoat Cote d’Ivoire AnthonothaFragrans_LB
Piptadeniastrum africanum Brenan Cote d’Ivoire PiptadeniastrumAfricanum_im
Guibourtia ehie J.Leon. Cote d’Ivoire GuibourtiaEhie_im_174
Manilkara huberi Standl. Bresil Amazonie ManilkaraSp._im_049
Pometia pinnata Forst. Salomon PometiaPinnata_im_127
Glycydendron amazonicum Ducke Guyane Francaise GlycydendronAmazonicum_LB
Cunonia austrocaledonica Brong. et Gris. Nouvelle Caledonie CunoniaAustrocaledonica_LB
Nothofagus aequilateralis Steen. Nouvelle Caledonie NothafagusAequilateralis_LB
Schefflera gabriellae Baill. Nouvelle Caledonie ScheffleraGabriellae_im_110
Gymnostoma nodiflorum Johnst. Nouvelle Caledonie GymnostomaNodiflorum_LB
Dysoxylum sp Nouvelle Caledonie DysoxylumSp._LB
Calophyllum caledonicum Vieill. Nouvelle Caledonie CalophyllumCaledonicum_im_1
Gyrocarpus americanus Jacq. Nouvelle Caledonie GyrocarpusAmericanus_LB
Pyriluma sphaerocarpum Aubrev. Nouvelle Caledonie PyrilumaSphaerocarpum_LB
Cedrela odorata L. Guadeloupe CedrelaOdorata_im_037
Moronobea coccinea Aubl. Guyane Francaise MoronobeaCoccinea_im_202
Goupia glabra Aubl. Bresil n.p. GoupiaGlabra_im_038
Manilkara huberi Standl. Bresil n.p. ManilkaraSp._im_049
Micropholis venulosa Pierre Guyane Francaise  MicropholisVenulosa_im_191
Cedrelinga catenaeformis Ducke Bresil Amazonie CedrelingaCatenaeformis_im_
Vouacapoua americana Aubl. Guyane Francaise VouacapouaAmericana_im_076
Tarrietia Densiflora Aubrev. et Normand Gabon TarrietaDensiflora_im_169