dBSkala

dBSkala, commonly referred to as the decibel scale, is a logarithmic scale used to express ratios of quantities such as sound pressure, power, or electrical voltage. It converts large multiplicative differences into additive differences, making it easier to compare levels that span wide ranges.

A decibel value represents a ratio and is defined differently depending on whether power or amplitude is being compared. For power ratios, dB = 10 log10(P/P0). For amplitude (with constant impedance), dB = 20 log10(V/V0). In acoustics, the reference for sound pressure level is p0 = 20 micro Pascals, yielding dB SPL = 20 log10(p/p0). The bel, the unit from which the decibel is derived, is defined as a log10 power ratio; the decibel is one tenth of a bel.

Common scales include dB SPL (sound pressure level), dB HL (hearing level, used in audiology), dBFS (full scale in digital audio systems), and dBm or dBW (power references in communications). The specific reference level defines the meaning of a value, but all decibel scales share the same underlying logarithmic basis.

Applications of the dBSkala span audio engineering, room acoustics, hearing assessment, telecommunications, and RF power measurements. Because the scale is relative, a value communicates how much a quantity differs from its reference rather than providing an absolute quantity. When combining levels, decibels are not added directly; they are aggregated through corresponding power ratios and then converted back to decibels.