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Sound Level Chart

Inside Home2545
Inside Office3550
Inside Airplane Cabin7585
Inside Factory65100
Talking @ 3 ft5565
Shouting @ 3 ft7585
Clothes Dryer @ 3 ft5565
Vacuum @ 3 ft6580
Chain Saw @ 3 ft100120
Clothes Washer @ 3 ft5575
Car @ 25 ft @ 65 mph7080
Airplane @ 1000 ft95110
Traffic @ 300 ft4060
Rural Ambient2535

Sound powers for the following equation in dBA units are referenced to a picowatt (10-12 W).

Sound Power Formula - RF Cafe

Where: W1, W2 = sound power in similar units of watts

The threshold of pain for the human ear is usually taken to be around 120 dBA.

One of the best compilation of noise power level data can be accessed in Chapter 5 of the Occupational Safety and Health Administration's OSHA Technical Manual website.

Loudness is the subjective human response to sound. It depends primarily on sound pressure but is also influenced by frequency. Three different internationally standardized characteristics are used for sound measurement: weighting networks A, C, and Z (or "zero" weighting). The A and C weighting networks are the sound level meter's means of responding to some frequencies more than others. The very low frequencies are discriminated against (attenuated) quite severely by the A-network and hardly attenuated at all by the C-network. Sound levels (dB) measured using these weighting scales are designated by the appropriate letter (i.e., dBA or dBC). The A-weighted sound level measurement is thought to provide a rating of industrial noise that indicates the injurious effects such noise has on human hearing and has been adopted by OSHA in its noise standards (OTM/Driscoll). In contrast, the Z-weighted measurement is an unweighted scale (introduced as an international standard in 2003), which provides a flat response across the entire frequency spectrum from 10 Hz to 20,000 Hz. The C-weighted scale is used as an alternative to the Z-weighted measurement (on older sound level meters on which Z-weighting is not an option), particularly for characterizing low-frequency sounds capable of inducing vibrations in buildings or other structures. A previous B-weighted scale is no longer used.

The following tables present examples of some common noise sources.

Noise Source
(at Given Distance)
Noise EnvironmentA−Weighted
Sound Level
Relative to 70 dBA
Military Jet @ Takeoff w/Afterburner50Carrier Flight Deck140128x
Civil Defense Siren100 13064x
Commercial Jet @ Take-off200 12032x
Threshold of Pain
Pile Driver50Rock Music Concert
Inside NY Subway
110 16x
Ambulance Siren
Newspaper Press
Gas Lawn Mower
Very Loud
Food Blender
Prop Plane Flyover
Diesel Truck
Boiler Room
Printing Press Plant
Garbage Disposal3Higher Limit of Urban Ambient Sound802x
Passenger Car, 65 mph
Living Room Stereo
Vacuum Cleaner
Normal Conversation
Air Conditioning Unit
Data Processing Center
Department Store
Light Traffic Large Business Office
Quiet Urban Daytime
Bird Calls (distant) Quiet Urban Nighttime 401/8x
Soft Whisper5Library and Bedroom at Night
Quiet Rural Nighttime
  Broadcast and Recording Studio 201/32x
Just audible
  Picowatt (10-12 W) power level01/128x
Threshold of hearing
Source: Compiled by Kimley-Horn and Associates, Inc., for the San Diego County government

The networks evolved from experiments designed to determine the response of the human ear to sound, reported in 1933 by a pair of investigators named Fletcher and Munson. Their study presented a 1,000-Hz reference tone and a test tone alternately to the test subjects (young men), who were asked to adjust the level of the test tone until it sounded as loud as the reference tone. The results of these experiments yielded the frequently cited Fletcher-Munson, or "equal-loudness," contours shown in the chart below.

Fletcher-Munson Contours, Sound Pressure Level Chart (OSHA) - RF Cafe

Fletcher-Munson Contours, OSHA

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