logarithmic ratio quantity · International / acoustics / signals · Modern
The decibel is one tenth of a bel and expresses a base-10 logarithmic ratio. It is not inherently a unit of sound pressure.
Converter
logarithmic ratio quantity · SI-compatible / electrotechnology / acoustics · Modern
neper
exact
- Record
- M564
- Definition quality
- Standardized
- Conversion mode
- formula
- Calculator
- Formula-based
Definition
The neper expresses logarithmic ratios using natural logarithms rather than base-10 logarithms.
Reference value
neper converts through a formula rather than a simple multiplier.
History & use
CIPM formally adopted neper for logarithmic quantities such as decrement, field level and power level defined with natural logarithms.
Modern use
Modern use is context-dependent and varies by region or measurement system.
Sources & evidence
Source tier — · confidence high
Related measurements
logarithmic ratio quantity · International · Modern
1 bel = 10 decibels. For a power-like ratio, 1 B corresponds to a ratio of 10:1.