Jul 31, 2023 · While the difference between a machine that runs at 26 decibels and one that runs at 32 decibels may not seem like a big deal, consider that with every 10-decibel increase in volume, the sound is actually doubling in intensity. For reference, a 30 dB sound is twice as loud as a 20 dB sound and half as loud as a 40 dB sound. Jul 29, 2020 · The phon is a unit of loudness that represents equal loudness to a 1000Hz tone. This means that if a tone is 90 phons it is equally loud as a 1000Hz tone at 90dB. If a 125 Hz tone is 47 phons, it is equally as loud as a 1000Hz tone at 47dB. The sone is the other unit of equal loudness. The conversion between phons and sones is shown in Equation 1: gSoLp.