ITU-T P.16-1989 Subjective Effects of Direct Crosstalk; Thresholds of Audibility and Intelligibility - Telephone Transmission Quality Study Group XII; 7 pp
The circuit noise is referred to the terminals of the subscriber’s set. Room noise is assumed to be negligible.
ITU-T P.16-1989 history
1989ITU-T P.16-1989 Subjective Effects of Direct Crosstalk; Thresholds of Audibility and Intelligibility - Telephone Transmission Quality Study Group XII; 7 pp