Sound Pressure Level: Difference between revisions

The term most often used in measuring the magnitude of sound. It is a relative quantity in that it is the ratio between the actual SOUND PRESSURE and a fixed reference pressure. This reference pressure is usually that of the THRESHOLD OF HEARING which has been internationally agreed upon as having the value .0002 dynes/cm2.

—  Source: [http://www.sfu.ca/sonic-studio/handbook/Sound_Pressure_Level.html SOUND PRESSURE LEVEL (SPL) http://www.sfu.ca]

<tr><td align="center"><b>Change in Sound Pressure Level dB</b></td><td align="center"><b>Approximate change in acoustic pressure</b></td><td align="center"><b>percentage change in acoustic pressure</b></td><td align="center"><b>Human Subjective Reaction</b></td></tr> <tr><td align="center">1dB</td><td align="center">1.1</td><td align="center">10%</td><td align="center">Can′t detect</td></tr> <tr><td align="center">3dB</td><td align="center">1.4</td><td align="center">40%</td><td align="center">Minimum change we can remember</td></tr> <tr><td align="center">6dB</td><td align="center">2.0</td><td align="center">100%</td><td align="center">Pressure doubling, significant change</td></tr> <tr><td align="center">10dB</td><td align="center">3.3</td><td align="center">330%</td><td align="center">Subjective doubling</td></tr> <tr><td align="center">20dB</td><td align="center">10.0</td><td align="center">1000%</td><td align="center">Very noticeable change</td></tr>  

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&mdash; Source: [http://www.diracdelta.co.uk/science/source/s/o/sound%20pressure%20level/source.html http://www.diracdelta.co.uk]