Noun
neper (plural nepers)
(electronics) A non-SI unit of the attenuation (or sometimes gain) of field and power quantities such as electronic signals; the natural logarithm of a ratio, with 1 Np (a ratio of 2.718:1) being equivalent to 8.686 dB.
Hence the neper and dB are related via: : and : The decibel and the neper have a fixed ratio to each other. Source: Internet