Sound insulation experiment

1. An Experiment On Effectiveness of different materials on sound insulation CC2007 Environmental Science (Group Presentation) Group Members: <ul><li>Wong Wai Sum , Sum (09081555A)

2. Li Hong Bin , Ben (10034164A)

3. LukWai Man , Ray (10094530A)

4. Lau CheokHei, Jeff (09090889A)

5. KanKaHim , Ken (10022177A)</li></li></ul><li>Content Background Introduction Experiment Objective Experiment Procedure Result Analysis Further development Q & A

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

11. What is sound?? Sound is a mechanical wave <ul><li>also a kind of longitudinal wave which does not have Polarization(偏震)</li></ul>produced by vibrations of objects require medium for propagation example: air, water cannot travel in vacuum

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

17. Sound Insulation Experiment Apparatus:

18. <ul><li>Dimension of the shoe box = 29cm x 19cm x11cm = 6061cm3

19. Area of the opened part = 19cm x 11cm = 209cm2</li></li></ul><li><ul><li>Frequencies chosen:

20. Materials used:</li></li></ul><li>Sound Insulation Experiment Procedure: Cut out one side of the shoe box and place the cloths inside the box. Set up the apparatus following the sequence from A to D as shown in Fig. 1.1.

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.

23. Result and Discussion:

24. So, the greater the R, the greater the Sound Reduction Level is.

25. So, the smaller the T, the greater the Sound Reduction Level is.

26. Analysis: <ul><li>Assumption:

27. The unique sound source for the experiment is the frequency generator.

28. The background noise during the experiment is kept constant.

29. The reflection and refraction effects of sound are negligible.</li></li></ul><li><ul><li>Sources of error:

30. Unstable readings of decibel meter

31. Impact sound can transmit through the ground to the box due to the vibration of speaker.

32. For the sound transmitted through the material , the sound wave can be reflected inside the shoe box, which may be noise, and it may affect the reading.</li></li></ul><li><ul><li>The background noise may not be constant though out the experiment.

33. Maximum possible error of the measurement = 0.05dB x 2 = 0.1dB</li></li></ul><li>In Our Experiment Conclusion: <ul><li>The greater the R, the greater the Sound Reduction Level is. </li></ul>( R↑->Reduction Level↑) <ul><li>The smaller the T, the greater the Sound Reduction Level is.</li></ul>( T↓-> Reduction Level↑) <ul><li>The most effective sound insulation material :</li></ul>Steel board (2mm) <ul><li>The least effective sound insulation material :</li></ul>EPS foam (18mm), A4 paper - 50pcs (5mm)

34. Some Professional Insulation Materials features & benefits: <ul><li>high performance soundproofing material for reducing airborne noise.

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.</li></ul>QUIET BARRIER® HDSuperior soundproofing material for blocking noise for residential and commercial use.

38. features & benefits: <ul><li>cost-effective, low-profile sound blocking barrier

39. designed to reduce noise transmission in wall, floor & ceiling assemblies

40. replaces lead sheeting

41. available in sheets, rolls and "peel & stick" versions</li></ul>QUIET BARRIER® MDEconomical soundproofing material for blocking noise for residential and commercial use.

42. Comparison on QUIET BARRIER® HD & QUIET BARRIER® MD

43. features & benefits: <ul><li>blocks and absorbs noise while reducing structural vibrations

44. great for engine compartments and equipment closures where moderate noise blocking is required

45. easy to cut for custom installations

46. may be used behind drywall

47. available with peel and stick adhesive backing</li></ul>QUIET BARRIER® LD CompositeAcoustical vinyl barrier composite for blocking sound.

48. features & benefits: <ul><li>blocks and absorbs noise while reducing structural vibrations

49. great for engine compartments and equipment enclosures

50. available with peel and stick adhesive backing</li></ul>QUIET BARRIER® MD CompositeAcoustical vinyl barrier composite.

51. features & benefits: <ul><li>heavy duty noise blocking, decoupling and sound absorption in one composite material

52. available with peel and stick adhesive backing for easy installation

53. excellent material for machine and engine enclosures and compressor rooms</li></ul>QUIET BARRIER® HD CompositeMost effective acoustical vinyl barrier composite for blocking sound.

54. Comparison on LD Composite, MD Composite, HD Composite

55. Other insulation materials

56. Examples of floor system

57. Examples of wall system

58. Measures of soundproofing at home Paints the wall with latex paints <ul><li>reduce sound</li></ul>Install carpets on the floor <ul><li>absorb sound</li></ul>Install drapes or shutters on the windows <ul><li>absorb sound</li></ul>Soft furniture <ul><li>dampen sound waves</li></li></ul><li>Solid doors keep sound out of individual rooms install a clear window film provide a soundproofing buffer rearrange furniture E.g. place a filled bookshelf against a particularly noisy wall decorate room with rough surface finishings effect multiple distortion to the propagation of the wave

59. Q & A

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>

61. Reference “Sound Blocking Products – QUIET BARRIER® HD” . Soundproof Foam. 9 March, 2011 <http://www.soundprooffoam.com/quiet-barrier.html> “Sound Blocking Products – QUIET BARRIER® MD” . Soundproof Foam. 9 March, 2011 <http://www.soundprooffoam.com/econo-barrier.html> “Sound Blocking Products – QUIET BARRIER® LD Composite” . Soundproof Foam. 11 March, 2011 <http://www.soundprooffoam.com/value-barrier.html> “Sound Blocking Products – QUIET BARRIER® MD Composite” . Soundproof Foam. 11 March, 2011 <http://www.soundprooffoam.com/dura-barrier.html> “Sound Blocking Products – QUIET BARRIER® HD Composite” . Soundproof Foam. 11 March, 2011 <http://www.soundprooffoam.com/ultra-barrier.html>

62. ~ The End ~Thank You !

Sound insulation experiment

Raymond Luk

Sound insulation experiment