The purpose of this Recommendation is to describea subjective listening test method which can be used to evaluate the speech quality of Circuit Multiplication Equipment (CME). This Recommendation is intended for use with CME systems, such as those described in Recommendations G.763, G764/G.765, G.767, G768 ordescribed in G.769 which use digital speech interpolation (DSI) techniques. For subjective test evaluations of CME systems not using digital speech interpolation techniques, channel transcoder systems described in Recommendations G.761 [General characteristics of a 60-channel transcoder equipment] or G.762 [General characteristics of a 48-channel channel transcoder equipment], use Recommendation P.830.