Difference between revisions of "Sound Pressure Level"
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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. | 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. | ||
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— Source: [http://www.sfu.ca/sonic-studio/handbook/Sound_Pressure_Level.html SOUND PRESSURE LEVEL (SPL) http://www.sfu.ca] | — Source: [http://www.sfu.ca/sonic-studio/handbook/Sound_Pressure_Level.html SOUND PRESSURE LEVEL (SPL) http://www.sfu.ca] | ||
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<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> | <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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— Source: [http://www.diracdelta.co.uk/science/source/s/o/sound%20pressure%20level/source.html http://www.diracdelta.co.uk] | — Source: [http://www.diracdelta.co.uk/science/source/s/o/sound%20pressure%20level/source.html http://www.diracdelta.co.uk] | ||
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Latest revision as of 20:05, 14 January 2009
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.
SPL may be measured with a SOUND LEVEL METER weighted according to a specific frequency response pattern and termed SOUND LEVEL. The electroacoustic equivalent to SPL is measured with a VU METER.
— Source: SOUND PRESSURE LEVEL (SPL) http://www.sfu.ca
| Change in Sound Pressure Level dB | Approximate change in acoustic pressure | percentage change in acoustic pressure | Human Subjective Reaction |
| 1dB | 1.1 | 10% | Can′t detect |
| 3dB | 1.4 | 40% | Minimum change we can remember |
| 6dB | 2.0 | 100% | Pressure doubling, significant change |
| 10dB | 3.3 | 330% | Subjective doubling |
| 20dB | 10.0 | 1000% | Very noticeable change |
— Source: http://www.diracdelta.co.uk