Calculate amplitude in dB and dBA from audio signal

1. How do you find amplitude from dB?
2. How do you calculate audio signal dB?
3. What is amplitude in dB?

How do you find amplitude from dB?

Decibels are a relative unit, they express the power of your signal relative to some reference power. If you are working with amplitudes, then the formula is: power_db = 20 * log10(amp / amp_ref); (See http://en.wikipedia.org/wiki/Decibel#Field_quantities).

How do you calculate audio signal dB?

The log of x² is just 2 log x, so this introduces a factor of 2 when we convert pressure ratios to decibels. The difference in sound pressure level between two sounds with p₁ and p₂ is therefore: 20 log (p₂/p₁) dB = 10 log (p₂²/p₁²) dB = 10 log (P₂/P₁) dB (throughout, the log is to base 10).

What is amplitude in dB?

Amplitude, reported on the decibel (dB) scale, measures sound's pressure or forcefulness. The more amplitude a sound has, the louder it is. In daily life, we often think of this as volume.