- 1decibel (dB) is roughly the smallest change we can perceive.
- Doubling the amplifier wattage results in ONLY a 3dB increase in
volume ("slightly louder"). Switching from a 50 watt amplifier
to a 100 watt amplifier or from a 100 watt amplifier to a 200 watt
will only increase the volume by 3 dB as long as you use the same
speakers.
- In order to double the current volume requires
roughly a 6 to 10 dB increase. A 6 dB increase
requires 4 times the power! and a 10 dB increase
requires a 10-fold increase in amplifier power.
Sound Levels
barely audible 0 dB - Threshold of
hearing
10 dB - Rustling leaf
20 dB - very quiet - Quiet room
30 dB - Soft whisper
40 dB Quiet library
50 dB Average home
60 dB - moderately loud. Ordinary conversation, Light
traffic.
70 dB - Vacuum cleaner, Heavy traffic
80 dB - Very loud. Garbage disposal.
90 dB - Diesel truck
100 dB - Snowmobile, Motorcycle, Train, garbage
truck, 15th row of rock concert, chainsaw,
Level - 5 to 10 using
earbuds and a standard IPOD or walkman. Uncomfortably loud.
110 dB - Jackhammer, power saw, symphony orchestra,
front row of rock concert, Car horn. Extremely loud
120 dB - Rock concert, Jet engine. Painful.
Threshold of pain.
Permanent Hearing Loss
Decibel Exposure Time Guidelines
Accepted standards for recommended permissible exposure
time for continuous time weighted average noise, according to NIOSH and CDC,
2002. Each 3 decibel (dB) increase above 85 decibels cuts the permissible
exposure time in half. Exceeding these times will likely
result in permanent hearing loss.
|
Continuous dB
|
Permissible Exposure Time
|
|
85 db
|
8 hours
|
|
88 dB
|
4 hours
|
|
91 db
|
2 hours
|
|
94 db
|
1 hour
|
|
97 db
|
30 minutes
|
|
100 db
|
15 minutes
|
|
103 db
|
7.5 minutes
|
|
106 dB
|
3.75 min (< 4min)
|
|
109 dB
|
1.875 min (< 2min)
|
|
112 dB
|
.9375 min (~1 min)
|
|
115 dB
|
.46875 min (~30 sec)
|
|
