Nov 27th, 2013 - Category: Sound
After over 15 years of working with customers and training salespeople in acoustics and vibration, a few simple rules of thumb come up over and over. Here are one of my favorites and a great graphic that gives a visual representation of decibels. The graphic below is from HEAROS, maker of the “Sleep Pretty in Pink” earplug. Looks like lime green earplugs are out of style now…
Happy Thanksgiving!
- 20 dB = one order of magnitude - 20 Log10 (10)
- 10 dB = half an order of magnitude - 20 Log (3.16)
- 6 dB = doubling of pressure - 20 Log10 (2)
- 94 dB = 1 Pa
For example : A Jet Engine at 100 ft might put out 150 dB. To calculate the level in Pascals directly would require a calculator (632 Pa). Since 94 dB equals 1 Pascal, a shortcut uses the fact that this would be two orders of magnitude (134 dB, 100 Pa) times half an order of magnitude (144 dB, 316 Pa) times a doubling of pressure (150 dB, 632 Pa). So without a calculator, it can be determined that a 50 mV / Pa microphone would generate 31.6 volts at 150 dB, above the maximum level for most DAQ systems.
Decibel Levels
