olemus
(1) ISO/IEC TR 11801, ISO/IEC 14776 jm, sumbumine:
signaali tugevuse vähenemine edastusel
= decrease in magnitude of power of a signal
in transmission between points

(2a) ISO/IEC 14776-121 sumbetegur:
väljundtugevuse ja sisendtugevuse skalaarsuhe või
selle suhte logaritm detsibellides
= a decrease in signal magnitude from one point to another; attenuation may be expressed as a scalar ratio of the input magnitude to the output magnitude or in decibels as 20 times the log of that ratio

(2b) ISO/IEC 14776-121:
võimendusteguri pöördväärtus
= reciprocal of gain

ülevaateid
https://en.wikipedia.org/wiki/Attenuation

https://www.dataloggerinc.com/wp-content/uploads/2016/11/16_Basics_of_signal_attenuation.pdf

https://www.phase-trans.msm.cam.ac.uk/2000/amjad/b.pdf