<span>Acoustic energy harvesting is one o</span><span lang="EN-US">f</span><span> many ways to harness </span><span lang="EN-US">acoustic </span><span>noises as wasted energy into use</span><span lang="EN-US">f</span><span>ul </span><span lang="EN-US">electical </span><span>energy using an acoustic </span><span>energy harvester. </span><span>Acoustic </span><span>energy harvester t</span><span lang="EN-US">h</span><span>at tested by Dimastya (2018) </span><span lang="EN-US">which is consisted of loudspeake</span><span>r </span><span lang="EN-US">and Helmholtz resonator, </span><span>produced two-peak spectrum. It is </span><span lang="EN-US">suspected</span><span> that the </span><span lang="EN-US">f</span><span>irst peak </span><span lang="EN-US">is due t</span><span>o </span><span lang="EN-US">Helmholtz</span><span> resonator resonance and the second peak </span><span lang="EN-US">comes</span><span lang="EN-US">from the resonance of the conversion </span><span>loudspeaker. </span><span lang="EN-US">This research is to experimentally confirm the guess of the origin of the first peak. The experiments are performed by adding silencer materials on the resonator inner wall which are expected to be able to reduce the height of first peak and to know </span><span>how </span><span lang="EN-US">they</span><span> a</span><span lang="EN-US">ff</span><span>ect t</span><span>he output electric power spectrum o</span><span lang="EN-US">f</span><span> t</span><span>he acoustic energy harvester. </span><span lang="EN-US">Three different silencer materials are used, those are</span><span> glasswool, acoustic </span><span lang="EN-US">f</span><span>oam, and styro</span><span lang="EN-US">f</span><span>oam</span><span lang="EN-US">,</span><span> with</span><span lang="EN-US"> the same thickness of</span><span> 12 cm. </span><span lang="EN-US">The r</span><span>esult</span><span lang="EN-US">s</span><span> show that glasswool absorb</span><span lang="EN-US">s</span><span> sound more e</span><span lang="EN-US">ff</span><span>ectively than acostic </span><span lang="EN-US">f</span><span>oam and styro</span><span lang="EN-US">f</span><span>oam. The use o</span><span lang="EN-US">f</span><span> glasswool, acoustic </span><span lang="EN-US">f</span><span>oam, and styro</span><span lang="EN-US">f</span><span>oam with 12 cm thickness lowered the </span><span lang="EN-US">f</span><span>irst peak </span><span lang="EN-US">by</span><span> 90% (</span><span lang="EN-US">f</span><span>rom 39 mW to 0,5 mW), 82% (</span><span lang="EN-US">f</span><span>rom 39 mW to 0,7 mW), and 82% (</span><span lang="EN-US">f</span><span>rom 39 mW to 0,7 mW), respectively. </span><span lang="EN-US">Based on these results, it is concluded that the guess of the origin of the first peak is confirmed.</span>
The effect of type of sound damper material in the Helmholtz resonator to the output power spectrum of acoustic energy Harvester
