Evaluation of the Suitability of Acoustic Characteristics of Electronic Demung to the Original Demung

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1 Indin Journl of Science nd Technology, Vol 8(S7), , April 2015 ISSN (Print) : ISSN (Online) : DOI: /ijst/2015/v8iS7/64718 Evlution of the Suitility of Acoustic Chrcteristics of Electronic Demung to the Originl Demung Heru Kuswnto 1*, Insih Wilujeng 1, Sptomo 2 nd Eko Arinto 3 1 Physics Eduction, Yogykrt Stte University, Yogykrt, Indonesi; herukus61@gmil.com 2 Music Eduction, Yogykrt Stte University, Yogykrt, Indonesi 3 Eduction nd technicl trining centers, Yogykrt, Indonesi Astrct The study ws conducted to evlute the suitility of coustic chrcteristics of electronic demung with originl demung. Demung is one of the importnt instruments in the gmeln, trditionl music ensemle in Indonesi which involves no less thn 70 instruments. Electronic demung ws mde in n ttempt to minituriztion of gmeln instruments which re generlly lrge nd hevy. Acoustic chrcteristics studied were wveforms, timre nd spectrogrm. Product testing ws lso conducted y questionnire to techers of music nd mster of gmeln. The nlysis showed tht the fundmentl frequency for ech key of electronic demung ws slightly higher thn the key of the originl demung. The increse in the fundmentl frequency of the keys in one octve, oth hve similr tendency. The numers of overtones of the originl demung were more thn tht of electronic demung. ED is considered useful ecuse it cn e esier to introduce gmeln music nd esy to crry. Keywords: Demung, Electronics, Gmeln 1. Introduction Gmeln is trditionl Indonesin musicl ensemle. We cn find it esily in Jv nd Bli. Now one cn find gmeln oth in Europe nd Americ. Gmeln ttrcts reserchers ecuse of its uniqueness of it which differs from western music. Gmeln does not hve stndrd tuning system. Although there re two tuning systems re pelog (seven keys to one octve) nd slendro (five keys to one octve), ut ech of gmeln instruments is tuned to set of the gmeln itself. Reserchers from Indonesi nd rod re generlly interested in the rt of plying the gmeln nd its content mening 1-7. Vrious reserches on coustic chrcter of gmeln were lso conducted in order to understnd the model of tuning nd compring it with western music The term gmeln cn lso refer to set of musicl instruments. One set of gmeln (pngkon) cn rech no less thn 70 instruments. These instruments re generlly mde of ronze, lloy of copper nd tin. Ech instrument is plyed one note or key. These instruments re grouped y function. One group is hving role s the min melody. This function is performed y group of instruments clled lungn. There re three types instruments tht ply lungn i.e. demung, sron, nd peking ech hve one octve. Demung hs octve lower thn sron. Peking hs the highest octve. The numer of instruments on demung is depending on the type of tuned, pelog or slendro. Demung nd pelog hs seven keys, slendro hs five keys. Mny groups tried to gin rtificil gmeln lighter thn the originl gmeln. Attempt to crete rtificil gmeln hs een crried out y some group oth in Indonesi nd rod. This encourged the need to otin the gmeln instruments tht cn e trnsported esily. The group of the University of Din Nuswntoro Semrng (UDINUS) 14 hs ttempted to ply musicl y using portle computers. Ech portle computer *Author for correspondence

2 Heru Kuswnto, Insih Wilujeng, Sptomo nd Eko Arinto contins progrm tht cn represent one group of instruments. Therefore, we need portle computer tht is equl to the numer of group to e plyed. A similr effort hs een mde y Joko of Premun Keumen 15. Group of the United Kingdom lso offers downlodle virtul gmeln 16. Group of Msschusetts Institute of Technology (MIT) comines western musicl instruments with gmeln clled Glktik. Some gmeln instruments formed from comintion of resistors, piezos nd cpcitive sensitive sensing 17,18. Gmeln smpul try to comine lptops nd sensing devices tht re outside. This comintion produces sound similr to gmeln 19. In this study, the instrument tht hs een mde does not require portle computer t the time of ply. Plyers cn crry esily ecuse of its smll size. Thus, the instrument cn e used to ssist students in lerning nd ply gmeln without hving to hve set of gmeln or portle computer, lthough we recognize tht plying originl gmeln is ctully etter. Electronic gmeln is mde of n electronic device tht is filled with the sound of the originl gmeln. In this pper we report on the suitility of coustic chrcteristics of electronic demung (ED). For comprison the originl demung (OD) of gmeln in Krwitn Lortory Fculty of Lnguge nd Art, Stte University of Yogykrt, Indonesi ws used. 2. Methods The first step, we recorded the sound of instruments. Figure 1 shows the set-up of equipment tht is used to record the sound of OD. The numer of keys in the OD re seven, mening tht this OD used on pelog tuning. Microphone is plced t distnce of 15 cm ove OD. Microphone is connected to the personl computer (PC). OD is plyed y the third uthor. He is lecturer nd performer of the gmeln. PC opertor recorded the sound just fter the OD eten. Recording ws stopped when the sound disppers. Beting is done five times. The next eting is done when the sound of the previous eting disppers. Dt is stored on PC. The second step ws to design circuit ord which will e filled with electronic devices. The min circuit design is tken from the dt sheet P8942A 20. The sound e conditioning so tht the sound source cn e stored in the IC recorder. Sound sources otined from the OD were previously recorded. The recorded sound wve hs formt with the extension *.wv with dt width of 32 Figure 1. The rrngement of instrument to extrct the coustic dt from the OD. its nd smpling rte of 44.1 khz frequency. To e t the input to the IC recorder, recording formt to e chnged with the file formt *.wv or *.voc with smpling rte of 8 its nd mono chnnel. Sound editing process ws implemented using sound editing softwre. Figure 2. nd Figure 2. show the product. In the ox of ED there re seven uttons. These uttons replce the function of the key on the OD. When this utton is pressed, it will produce the sme sound with the sound of key in the OD. The size of this ox is 5cm 7cm 15cm with weight of 0.3kg, mking it esy to crry. The product test ws performed s previously recorded stge. The position of OD ws replced with ED. When the utton of ED is pressed, the recording is done, nd then stored in the PC. Product testing ws lso conducted y questionnire supplied to techers of music nd mster of gmeln. To mesure the performnce of the product, instrument rting scle form were given to techers nd msters to use the sme sttement. The sttement in the instrument is grouped into: the effectiveness of the design, ese of use, consistency, orgniztion, nd expediency. 3. Results nd Discussion Figure 3 shows n exmple of wveforms otined from () the OD nd () ED. Both were tken from key # 2. Wve forms re tken t the eginning. The wveform of the OD showed five rditing wves together. This sitution is different from tht of produced y ED. There re two wves tht run long. Figure 4 is spectrum of () OD, nd () ED. Spectrum ws tken with the Fst Fourier Trnsform. The numer Indin Journl of Science nd Technology 123

3 Evlution of the Suitility of Acoustic Chrcteristics of Electronic Demung to the Originl Demung Figure 2. () The min components in ED nd () The outside of the ED. There re seven uttons, ech hve function like the key of ED. Figure 3. The wveform otined from the #2 key () of OD nd () of ED. Figure 4. The spectrum otined from the #2 key () of OD nd () of ED. of smples tken is Windows tht is used is Blckmn-Hrris. Spectrum peks normlized to the highest pek. The frequency tht hs the highest intensity for the #2 key of OD is 323 Hz, while the ED is 396 Hz. This frequency is the fundmentl frequency, frequency which mrks the tone produced y musicl instrument. The fundmentl frequency followed y overtones which hve lower intensity. This ehvior is chrcteristic tht differentites one musicl instrument with others though with the sme tone produced. OD nd ED hve six nd five overtone respectively. Figure 5 shows comprison of the fundmentl frequency generted y OD nd ED for the seven keys. The increse in the fundmentl frequency of the key #1 through #7 key prllels, lthough the frequency is not the sme vlue. These results re similr to results conducted Figure 5. Comprison of fundmentl frequency of OD nd of ED. y Surjodiningrt et l 8. They studied numers of fmous gmeln in Jogjkrt nd Surkrt. Fundmentl frequency for ech gmeln instruments re different, ut hve prllels in the increse in frequency etween the 124 Indin Journl of Science nd Technology

4 Heru Kuswnto, Insih Wilujeng, Sptomo nd Eko Arinto Tle 1. Comprison overtone frequencies generted y the OD nd the ED Keys numer of originl Demung (OD) Keys numer of electronics Demung (ED) #1 #2 #3 #4 #5 #6 #7 #1 #2 #3 #4 #5 #6 # keys. Similr results were otined y Kuswnto et l 13, when compring the fundmentl frequencies of the two gmeln Sekti of Krton (plce) of Yogykrt. This result ws relized considering tht the gmeln tuning is not sed on specific frequency s the western musicl instruments. Tuning of gmeln instruments dpted to the hrmony in the one set of gmeln 1,3. Tuners of gmeln rely on their ility of the trined hering. Tle 1 presents the numer of overtones for ech key. The vlue of the frequency hs een normlized to the fundmentl frequency. The vlue of one indictes the fundmentl frequency. Vlues in old, whose vlues pproximted n integer, show hrmonics of the fundmentl frequency. For OD, key # 1 nd # 2 do not hve hrmonic frequency. We see there is some frequency hrmonics on keys # 3, # 4, # 5, # 6 nd # 7. The keys of ED do not ll hve hrmonic frequencies. Even for key # 7 ws not followed nother frequency. Key # 4, # 5 nd # 6 followed y single frequency respectively. Tle 1 revels tht the keys of the OD hve numer of overtone frequencies greter thn tht produced y the ED. This indictes tht the electronic device reduces the numer of OD overtone. Fundmentl frequencies hve longer life time thn the overtone. This sitution is encountered in the OD nd ED s indicted y the spectrogrm in Figures 6 nd 6 respectively. Overtone which hs lower intensity vnishes more quickly. The results of the ssessment given y the mster of gmeln re slightly different from tht given y music techer s shown in Figure 7. In generl, the ssessment Figure 6. The spectrogrm otined from the #2 key () of OD nd () of ED. Figure 7. Results of the ssessment y the music techer nd mster of gmeln to ED. given y the music techer is higher thn the mster of the gmeln. The differences re so noticele for consistency nd orgniztionl components. Music techers rte higher these two components thn the mde y the Indin Journl of Science nd Technology 125

5 Evlution of the Suitility of Acoustic Chrcteristics of Electronic Demung to the Originl Demung mster of the gmeln. All the techers were sked to give n ssessment of the electronic gmeln is mking judgment tht this device is very useful. Usefulness reltes to: fcilitte students in lerning gmeln, lerning cn e done y plying, motivting children to lern gmeln, nd the price of the device tht cn e reched. 4. Conclusion The tendency of increse in the fundmentl frequency of ech key on the OD nd ED re equl. The fundmentl frequency of ech key of ED is higher thn tht of OD. ED is considered useful ecuse it cn e introduced to gmeln music esily nd esier to crry. 5. Acknowledgement The uthor cknowledges the support of Ntionl Strtegic Reserch Grnt of Yogykrt Stte University, Indonesi No. 239/STR/UN34.21/ References 1. Sumrsm. Gmeln: Culturl interction nd musicl development in centrl Jv University of Chicgo Press; Chicgo. 2. Tenzer M. Anlyticl studies in world music oxford. Oxford University Press; Crterette EC, Kendll RA. On the tuning nd stretched octve of Jvnese gmelns. Leonrdo Music J. 1994; 4: Aville from: stle/ Spiller H. Gmeln: the trditionl sounds of Indonesi. Snt Brr: ABC-CLIO, Inc.; Benmou M. Rs: Affect nd intuition in Jvnese musicl esthetics. Oxford: Oxford University Press; Gungming L. The effect of inhrmonic spectr in Jvnese gmlen tuning (I): theory of the slendro. Proceedings of the 7 th WSEAS interntionl conference on Acoustic & Music: Theory nd Applictions; 2006 Jun 13-15; Cvtt, Croti: p Becker J. Trditionl music in modern Jv. Honolulu: The University Press of Hwii; Surjodiningrt W, Sudrjn PJ, Susnto A. Tone mesurements of outstnding jvnese gmelns in yogykrt nd surkrt. Gdjh Md University Press; Rossing TD, Shepherd RB. Acoustics of gmeln instruments. Percussive Notes : Sethres WA. Tuning, timre, spectrum, scle 2nd edition. London: Springer; Merthys IGN, Prtomo B. The temporl nd spectrl chrcteristics of gmeln sund music. J Acoust Soc Am. 2008;123: Jones ME, Gee KL, Grimshw J. Virtionl chrcteristics of Blinese gmeln metllophones. JASA Express Letters [Internet] Apr 20; doi: / Kuswnto H, Sumrn, AP, Cipto BH. Sron demung instruments timre spectrum. comprison study on the gmelns sekti from. Krton Ngyogykrt. IJBAS. 2012; 12 (01): Aville from: ijs-ijens.pdf 14. [Accessed 2014 Dec 2]; Aville from: egmelnku.com/ 15. [Accessed 2014 Dec 2]; Aville from: muri/rekor/10-inventor/226-pencipt-progrm-komputervirtul-gmeln 16. [Accessed 2014 Dec 2]; Aville from: org.uk/modulegmeln.sp 17. Aville from: Prdue LS, Andrew B, Mtt B. Gmeln elektrik: n electronic linese gmeln Proceedings of the Interntionl Conference on New Interfces for Musicl Expression (NIME 11); 2011 My 30-Jun 1; Oslo, Norwy: p Wiridjy AO. Gmeln smpul: lptop sleeve gmeln. Proceedings of the Interntionl Conference on New Interfces for Musicl Expression (NIME 13); 2013 My 27-30; KAIST; Dejon, Kore: P Aville from: /APLUS/AP8942A/306/2/AP8942A.html 126 Indin Journl of Science nd Technology