Named after Alexander Graham Bell. We perceive differences in volume level in a logarithmic manner. Our ears become less sensitive to sound as its intensity increases. Decibels are a logarithmic scale of relative loudness. A difference of approx. 1 dB is the minimum perceptible change in volume, 3 dB is a moderate change in volume, and about 10 dB is an apparent doubling of volume.* 0 dB is the threshold of hearing, 130 dB is the threshold of pain.* Whisper 15-25 dB* Quiet background about 35 dB* Normal home or office background 40-60 dB* Normal speaking voice 65-70 dB* Orchestral climax 105 dB* Live Rock music 120 dB+* Jet aircraft 140-180 dB