Developments in the Application of Articulation Testing
Theodore G. Castner, C. W. Carter · Bell System Technical Journal · 1933
The first part of this paper discusses the control and measurement of variable factors involved in testing telephone circuits by the articulation method and the simulation of the testing conditions in the laboratory to those of actual use; the second part describes the auxiliary apparatus by which these controls and measurements are effected. This apparatus includes a caller's control circuit, by which the caller's speech intensity may be measured and regulated independently of the circuit tested; a switching system which automatically reverses the direction of transmission between test sentences; devices for automatic and uniform agitation of carbon button transmitters; equipment for automatic measurement of the magnitude of the speech and noise waves on the circuits tested; phonographic sources of line and room noise; and a control board at which circuit elements and conditions can be changed and measured quickly. In addition, the time required to carry out a program of tests has been materially reduced by the use of equipment which analyzes the articulation data automatically and provides the test results in typewritten form immediately after each list is called.