SINGLE THREAD

Decibel Level

Written by Bryan on January 25th, 2010 in Health, Health Advisory.

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For some reason, people are requesting information on decibel levels all over the place.
So here is some information on what it really is.

According to the all-knowing Wikipedia decibel level is

The decibel (dB) is a logarithmic unit of measurement that expresses the magnitude of a physical quantity (usually power or intensity) relative to a specified or implied reference level. Since it expresses a ratio of two quantities with the same unit, it is a dimensionless unit. A decibel is one tenth of a bel, a seldom-used unit.

The decibel is widely known as a measure of sound pressure level, but is also used for a wide variety of other measurements in science and engineering (particularly acoustics, electronics, and control theory) and other disciplines. It confers a number of advantages, such as the ability to conveniently represent very large or small numbers, a logarithmic scaling that roughly corresponds to the human perception of sound and light, and the ability to carry out multiplication of ratios by simple addition and subtraction.

And here is a common decibel chart

Environmental Noise
Weakest sound heard	0dB
Whisper Quiet Library	30dB
Normal conversation (3-5′)	60-70dB
Telephone dial tone	80dB
City Traffic (inside car)	85dB
Train whistle at 500′, Truck Traffic	90dB
Subway train at 200′	95dB
Level at which sustained exposure may result in hearing loss	90 – 95dB
Power mower at 3′	107dB
Snowmobile, Motorcycle	100dB
Power saw at 3′	110dB
Sandblasting, Loud Rock Concert	115dB
Pain begins	125dB
Pneumatic riveter at 4′	125dB
Even short term exposure can cause permanent damage – Loudest recommended exposure WITH hearing protection	140dB
Jet engine at 100′, Gun Blast	140dB
Death of hearing tissue	180dB
Loudest sound possible	194dB

OSHA Daily Permissible Noise Level Exposure
Hours per day	Sound level
8	90dB
6	92dB
4	95dB
3	97dB
2	100dB
1.5	102dB
1	105dB
.5	110dB
.25 or less	115dB

Perceptions of Increases in Decibel Level
Imperceptible Change	1dB
Barely Perceptible Change	3dB
Clearly Noticeable Change	5dB
About Twice as Loud	10dB
About Four Times as Loud	20dB

Sound Levels of Music
Normal piano practice	60 -70dB
Fortissimo Singer, 3′	70dB
Chamber music, small auditorium	75 – 85dB
Piano Fortissimo	84 – 103dB
Violin	82 – 92dB
Cello	85 -111dB
Oboe	95-112dB
Flute	92 -103dB
Piccolo	90 -106dB
Clarinet	85 – 114dB
French horn	90 – 106dB
Trombone	85 – 114dB
Tympani & bass drum	106dB
Walkman on 5/10	94dB
Symphonic music peak	120 – 137dB
Amplifier rock, 4-6′	120dB
Rock music peak	150dB