this is a presentation for the intern noise in 2023 I am Gaya parikosit from universitas schedule in Indonesia the title of my presentation is how the building and string material affects its musical sound first I will explain what the bundungan is as is shown in the picture the bundungan is a musical instrument that is made mainly from bamboo and it is shaped like a dome player wants to play this instrument the player sits inside the instrument cross select this unique musical instrument is originated from bonusobo in Central Java the sound of the bundungan imitates the sound of the gamelan orchestra and particularly the strings imitate the sound of the gong compul kanong and elements in the gamalan there are mainly two types of sound generators in the bundanan the bamboo bars and the loaded strings first let's take a look at the bamboo bars at the left side we can see a zoomed in version of the picture where we can see three bamboo bars the building and players use their fingers to pluck these bamboo bars to imitate the sound of leather drums besides the bamboo bars there are also the loaded strings these are strings that are equipped with bamboo Clips as the mass loading extra on the strings so far we have already three papers presented in the intern noise conference the first one was presented in 2020 with the title of why the Bunnings is a personal musical instrument and then the year after we presented another paper which was titled the effect of bamboo clip Dimension and position towards the frequency spectrum of a vibrating in homogeneous bundingan string for this year we are presenting a new paper which is titled how the bullion and string material affects its musical sound so originally the building on strings were made out of sugar Palm fibers so in the old days the buningan players take sugar bomb fibers make ropes out of it and then use them as strings however in the modern days we now use various types of badminton strings so far there were there are no study that discusses about how the different materials affect the sound of the bundingan sound here we have six types of strings in our study the first five the first five strings are badminton strings and the last one is the sugar Pond fiber strings between the five Batman badminton strings we have different structures and different materials as well the first one is a multivitamin with single wrap the second one is multi-core with single wrap and then the third one multi filament with double wrap and the fourth one is solid core with single wrap the fifth one is pretty special it's from natural gut it's the most expensive one and also the material that is usually used in a violin or other string instruments here we can see from the table the different brand we use for the different string materials and also the diameters of the different strings the first three badminton strings have the same diameter which is 0.66 millimeters but the fourth one is a bit thicker and also the fifth one is even thicker for the sugar pound fiber string it's actually the thinnest one but it's varying between 0.3 until 0.5 millimeter in diameter we perform several Acoustics analysis of the different strings first of all we built a setup where we can test the strings and we plot the strings so that we can measure the data of the sound and then we compare our measurements with calculations for the calculations We Begin our model using the ideal string model but then we further improve the quality of our model by taking into account the stiffness of the string when we compare the data with the theory we do it in two domains the first one is in the frequency domain and the second one is in the time domain in the frequency domain we see the frequency Spectra of the sound when we block the booting on strings and then we identify the frequency values of the first four picks in the Spectra as far in the time domain we see how the sound decays so we use our measurement of the sound to identify how quickly the amplitude of the wave decays along the time here are the results of our analysis first let's compare the properties between the six different string materials first we can compare the linear density here we can see that the minimum the the smallest linear density is the linear density of the sugar bomb fibers well the highest in your density belongs to the Natural gut strings and then our measurements and calculation leads to the value of the young modulus of the six different strings where again we have different properties now we have the sugar Palm fibers as the string with the highest young modulus and then we also calculate the sound radiation coefficient which shows which of the strings give the loudest sound as you can see from the graph the sugar pump fibers have the maximum value of the sound radiation coefficient and this means the sugar Palm fibers give away the loudest sound among the different string materials now we can compare the measurements and the calculations from the data of the frequency Spectra and we do this for four different elements in the gum line we will begin with the gong and then we will continue with the other element with the gong We compare between measurements and calculations for six different materials and we do this for the first for peaks in the frequency Spectra from the graph we see that the minimum error or the minimum frequency difference is obtained when we use the natural gut in particular the first peak of the natural gut frequency spectrum give almost zero very small frequency difference between the measurements and the calculations as for the second element we now have the compo the compo has a higher frequency than the previous element the gone when we compare which one has the smallest frequency difference we see a different result here compared to the gong we have different Trends and also different behaviors between the different string materials we also have different results for the third element which is the Canon here we again compare the six different materials and we compare also the first Four Peaks in the frequency Spectra for each of the materials and the last element the fourth element is we again compare the six different string materials and we perform analysis on the first Four Peaks in the frequency Spectra as I said before our analysis is not only performed in the frequency domain but also in the time domain so in the time domain we can now compare the damping ratio between the six different materials the string materials and we do this also for the four different elements in the gamlan orchestra which is the gong compul kanong and Kato for the damping ratio we would like to have the string materials that reverberates the longest so in conclusion we have several data and several results from our analysis first of all if we would like to have the loudest sound we can choose the string materials which have the maximum sound radiation coefficient and this is the sugar pound fiber strings which has been traditionally traditionally used from the old days and if we want to be able to calculate the frequency values and have low errors in our calculations compared to the measurements then we can use either natural gut for the gong compul and katuk or we can also use the solid core with single wrap badminton string and that is suitable for the Canon element in the gamlan orchestra more than that we can also choose the string materials based on the damping ratio and in this point of view the natural gut is the best one because the natural gut have the slowest decay of sound which allows the boonding and player to generate sound that closely imitates the gamelan sound so that is my presentation for the internal noise 2023 thank you for your attention and feel free to post any questions related to this presentation thank you very much