Decibels are also used to measure the power of electrical signals.
This article pertains to the measurement of sound.
What Is a Decibel (dB) in Music?
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A decibel, designated by the letters dB, is a logarithmic scale of loudness.
Our ears detect changes in volume in a non-linear fashion.
Sound loudnesswhich is not necessarily the same thing as volumeis determined by a variety of factors.
The Decibel Scale
The decibel scale was created to quantify how loud sounds are.
A difference of 1 dB is perceived as a minimum change in volume.
The threshold of hearing is 0 dB.
A receiver with 100 WPC needs to be 1,000 WPC to be twice as loud.
This is because more power output is required at lower frequencies to produce the same volume level.
A video projector with a fan noise rating of 20 dB or less is considered very quiet.
How to Measure Decibels
One way that decibels can be measured is with a portable sound meter.
There are also sound meter apps that work with the microphone in a typical smartphone.
A microphone is provided that plugs into the front of the receiver.
