Decibel Sound Pressure Level expresses the sound pressure level relative to 20 micro Pascal (µPa). 20 µPa at 1 KHz is the weakest sound level a person with normal hearing can hear and is defined as 0 dB SPL. Sound pressure at 20,000 µPa is equivalent to 60 dB SPL, which is where you hear normal speech.
robotic regards,
Tom
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Whereas *security* deals with "external intrusion" into our computers, *privacy* is concerned with issues of "internal extrusion".
- - Steve Gibson |