Week 6 - People
5. Noise
5.3. Noise Control
Typical sound levels
Changes in sound levels
Sound Level Change | Effect on Hearing |
-/+ 1 dB | negligible |
-/+ 3 dB | just noticeable |
+ 10 dB | twice as loud |
- 10 dB | half as loud |
+ 20 dB | four times as loud |
- 20 dB | one-quarter as loud |
Noise Control – Action Areas
1. Source of Sound
Eg from outside the building, or within the building
2. Sound Path
Eg through the air, or through the building structure
3. Receptor/Receiver of Sound
Eg the building itself, a particular room, or a person.
Noise Control - Treatments
When controlling noise it is sensible to work through the action areas in the following order.
1. Source of sound – can it be stopped or reduced in energy.
Eg: changing or treating noisy machinery, noisy people
2. Path of sound – can the noise be reduced during its transmission through the air or a structure
Eg: distance from source, stopping air gaps, increasing sound insulation of structures
3. Receiver of sound - can it be protected
Eg: Insulating a building, or room. Wearing ear defenders