Abstract :
The circuit noise-meter (or psophometer) is an instrument which has been designed for measuring the disturbing effect of power induction on telephone conversation. Measurements have indicated that some form of frequency weighting in the instrument is desirable. The proposed C.C.I.F. specification for the instrument is quoted and discussed. Some useful applications of the psophometer are given. The limitations of present models as applied to other types of noise are reviewed.
