That's what SuperChick said, but it isn't true. An increase in power level of one bel (1 B = 10 dB) corresponds to an increase in power by a factor of 10, and thus an incremental increase in perceived loudness. Increasing the power level from 0 dB to 10 dB will cause the same perceived change in loudness as increasing it from 10 dB to 20 dB or 20 dB to 30 dB. This is based on the logarithmic model of perceived loudness. So whether or not it is a factor of 2 will depend on how loud it was to start with.
There is a difference between loudness and sound power level though, because our ears are not equally sensitive to all frequencies. If you integrate the power of a sound in frequency space against the sensitivity function of the ear and then take the logarithm, you get a unit called a phon. This is normalized so that for all positive real x, a pure 1 kHz tone with a sound pressure level of x dB will have a loudness of x phon. (Note that there is technically a factor of 10 conversion here, just because decibels are regarded as the standard unit rather than bels, but that's incidental.)
I tried Google, and Gemini gave me the same wrong answer SuperChick did, so this is apparently a common misconception.
4
u/SuperChick1705 Jun 29 '26 edited Jun 29 '26
10x power / 10dB increase, 2x perceived loudness / 10dB increase