6. What is noise? Noise can be a very Loud sound Low-level sound but annoying
7. Loud Noise in Hong Kong The main concern of noise :Traffic Noise It affects more than one million people 655 roads generate noise greater than 70 dB But only 101 of these roads applied barriers
8. What can we do personally? Choose some good sound insulating materials to build your flat. Today, we are going to test which materials (commonly seen in our daily lives) are good at insulating sound !
9. Sound Insulation Experiment Objective To compare the sound insulation ‘s effectiveness of different materials under different frequencies in term of Sound Reduction Index(R) and Transmitted coefficient (T).
10. Materials to be tested… (1)the Expandable Polystyrene (EPS) foam (2)stainless steel (3)wood (4)A4 paper
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12. Where the sound from? Can be found easily in our daily life For example, Musical instrument Car Talking Aircraft take-off
13. Sound Insulation Insulate the sound we don’t want to hear The ability for the material to reduce the sound energy transmitted into an adjoining air space. Type of sound insulation: Airborne Sound Insulation Impact Sound Insulation
14. Airborne Sound Insulation the insulation against noise originating in air, e.g. voices, music, motor traffic, wind. Impact Sound Insulation the insulation against noise originating directly on a structure by blows or vibration
15. Insulated the sound by mean of … reflection absorption Sound would reflect at the surface of material so that only a part of sound energy will be transmitted. Also, material will absorbs the sound energy and dissipates in form of heat making the reduction of transmission of sound. result in reduction in sound level
16. Decibel meter using a decibel meter, we can measure the sound level (in dB) of different sound source. sound level (L) L = 10 log10 [ I/I0 ]…………………(1) sound reduction index (R): R = 10 log10 [ 1 / T ] (dB)…………(2) T: Transmitted sound energy / Incident sound energy
21. 3. Turn on the speaker and generate a frequency of 125Hz (f1). 4. Measure the sound level (L0) using the sound meter and record it in Table 1.1. 5. Put the Expandable Polystyrene (EPS) foam (material 1) in front of the shoe box to cover the opened part of the box. 6. Measure the sound level (L1) for three times using the sound meter and record them in Table 1.1.
22. 7. Repeat steps 2 to 5 for the remaining measurements using other frequency and material. 8. Calculate the average sound level (Laverage= (L1+L2+L3)/3), Sound Reduction Index (R) and transmitted coefficient (T) for different material under different frequency using equation (2). 9. Draw bar charts to show the relation between R/T and different frequencies for different materials.
31. Impact sound can transmit through the ground to the box due to the vibration of speaker.
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35. may be used behind drywall in wall and ceiling assemblies or sandwiched between existing and new drywall.
36. use in flooring systems to increase sound transmission class.
37. used for both residential and commercial soundproofing applications.QUIET BARRIER® HDSuperior soundproofing material for blocking noise for residential and commercial use.
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39. designed to reduce noise transmission in wall, floor & ceiling assemblies
41. available in sheets, rolls and "peel & stick" versionsQUIET BARRIER® MDEconomical soundproofing material for blocking noise for residential and commercial use.
53. excellent material for machine and engine enclosures and compressor roomsQUIET BARRIER® HD CompositeMost effective acoustical vinyl barrier composite for blocking sound.
60. Reference “How to Soundproof: Basic Principles”. Noise Help. 22 February, 2011 <http://www.noisehelp.com/how-to-soundproof.html> “Frequency-Dependent Sound Absorption”. Science Buddies. 28 February,2011 <http://www.sciencebuddies.org/science-fair-projects/project_ideas/Phys_p029.shtml> “Transmission of Sound” City University of Hong Kong. 1 March,2011 <http://personal.cityu.edu.hk/~bsapplec/transmis.htm> “Explore... Home Improvement: How Sound Insulations Work” Trans4mind Ltd. 1 March , 2011 < http://www.trans4mind.com/explore/home-improvement/19620.html > The Sound Solution – Soundproofing Materials & Sound Proofing Products <https://www.noisestopsystems.co.uk/> How to soundproof a room <http://www.howtoall.com/Homefiles/howtosoundproofaroom8.htm> How to Soundproof Rooms in a House <http://www.ehow.com/how_1000181_soundproof-a-room.html#ixzz1FyklcYCp>
![An Experiment On Effectiveness of different materials on sound insulation CC2007 Environmental Science (Group Presentation) Group Members: ,[object Object]](https://image.slidesharecdn.com/soundinsulationexperiment-110312222214-phpapp02/85/Sound-insulation-experiment-1-320.jpg)
