190 likes | 324 Views
Apply sound transmission to soundproofing. Koshi high school 2 nd gRade Tomohiro Iwata Yuto Ochiai Takaki Saito Kyohei Yamamoto . Motivation.
E N D
Apply sound transmission to soundproofing Koshihigh school 2ndgRade Tomohiro Iwata Yuto Ochiai Takaki Saito Kyohei Yamamoto
Motivation • When our school is under construction, the noise will have a bad influence on our class. We considered how we can reduce the noise and studied how the thickness of a material affects sound transmission. • In the end, we want to find the cheapest and easiest way to reduce sound transmission.
What is sound transmission? Reflected sound energy Absorbed energy Transmitted sound energy Incident sound energy
Experiment Use 1-6 boards 12mm or 5.5mm thick 12mm 48mm
Experiment equipment Speaker device Constant-frequency oscillator PC
Front view microphone speaker
Expectation We thought sound gets smaller and smaller by adding boards.
Fft(fast fourier transform) percentage of frequency occurring sound Noise ( outside the area of measurement) percentage of frequency frequency
Experimental landscape -20 -40 -60 -80 -100 dB(sound level)
Experiment result Fft(fast fourier transform) representing sound in terms of the frequencies of the waves that make up that signal percentage of frequency percentage of frequency frequency frequency
Experiment result Red 0mm green12mm blue24mm yellow36mm light blue 48mm pick 60mm white 72mm As the number of boards increases, we don`t see sound insulation effect.
Consideration Ⅰ Contrary to expectations, the sound didn’t increases in proportion.
Consideration Ⅱ Asymptote It seems that this graph has an asymptote.
Consideration Ⅲ There will never be a point where sound isn’t transmitted at all.
Consideration Ⅳ Transmission loss (dB) • Thickness of board(mm)
Consideration Ⅳ transmission loss (dB) Thickness of board(mm)
truss structure • Incident sound • Reflected sound • Transmitted sound
Our next challenge measure sound transmission USING A truss structure (which LOOKS LIKE THE CROSS SECTION OF CARDBOARD). Make space between THE BOARDS,AND STUDY THE difference FROM when THE boardS ARE attachED. CONFIRM THE asymptote of THE graph.