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Housing Material Products

Tidbits of Knowledge on Soundproofing

Glossary of Soundproofing Terms

Sound insulation
Sound insulation is a means of soundproofing by reflecting as much sound as possible.
The smaller the sound leakage from or into a certain space, the higher the sound insulation.
Example:
Blocking the sound of a piano or stereo from being heard outside the room.
Blocking outside sounds from entering a room.
Representative sound insulating materials: steel plates, sound insulating sheets, lead sheets, plasterboard

Sound absorption
When sound passes through material with many small holes in it, the sound waves are attenuated. Material that permits large portion of sound to pass through the holes and reflects minimal portion of it is said to have good sound absorbency.
Example: Reducing the echoing of sound in a room
Representative sound absorbing materials: glass wool, rock wool, rock wool sound absorbing board

Vibration damping
Vibration damping is a means of reducing vibration in a short period of time to prevent vibration noise.
Example:
Stopping the vibration (sympathetic vibration) of air conditioners and refrigerators.
Reducing the noise generation of flooring material.
Representative vibration damping materials: vibration damping sheets, rubber sheets


Vibration proofing
Vibration proofing is a means of reducing the transmission of vibration.
Example:
Reducing the transmission of noise and vibration caused by people walking overhead.
Reducing vibration.
Reducing the transmission of low pitched sound from stereos.
Representative vibration proofing materials: rubber mats, felt

Noise Levels in Daily Life

20 Faint ● Ticking of a clock
● Sound of breathing
40 Moderate ● Air supply sound of an air-conditioner
● Whisper
● Residential area during the daytime
60 Common sounds ● Alarm clock
● Running water in a stainless steel sink
● A wooden door closing
80 Loud ● Flush toilet
● Shout
● TV at a high volume
● Radio
100 Extremely loud ● Disco
● Inside a Karaoke booth
● Inside a noisy factory
120 Painfully loud ● Beating of a drum
● Rock music
● Thunder nearby
● Under a railroad bridge
2 units of measurement that express noise level
dB (decibels)
dB is a unit of measurement that expresses the level of sound with higher values expressing louder noise. The unit that expresses audible sound to human ears is dB(A).
Hz (hertz)
Hz is a unit of measurement that expresses sound frequency. This unit expresses the number of cycles per second. Smaller values express lower frequencies.

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