Wednesday, February 23, 2011

Loudnessss !


Sound loudness is a subjective term describing the strength of the ear's perception of a sound. It is related to sound intensity, but can't be considered identical to intensity. Sound intensity is the power per unit area.

Environmental Noise
Weakest sound heard0dB
Whisper Quiet Library30dB
Normal conversation (3-5')60-70dB
Telephone dial tone80dB
City Traffic (inside car)85dB
Train whistle at 500', Truck Traffic90dB
Subway train at 200'95dB
Level at which sustained exposure may result in hearing loss90 - 95dB
Power mower at 3'107dB
Snowmobile, Motorcycle100dB
Power saw at 3'110dB
Sandblasting, Loud Rock Concert115dB
Pain begins125dB
Pneumatic riveter at 4'125dB
Even short term exposure can cause permanent damage - Loudest recommended exposure WITHhearing protection140dB
Jet engine at 100', Gun Blast140dB
Death of hearing tissue180dB
Loudest sound possible194dB

Long time exposer to these loud decibels can cause ear and brain damage. For example, 110 Decibels Regular exposure of more than 1 minute risks permanent hearing loss.


  1. good start
    good graphics

    How loud is it in the school? How loud is each classroom? How loud should a classroom be? How loud can you be? How loud is...? How do loudness & distance go together (equation/relation)?

    please finish