Abstract: The voice quality of telephone calls is evaluated. A first connection is established between a computerized apparatus and a person acting as a first experimenter, and a second connection is established between the platform and a second experimenter. The first and second connections are interconnected by the computerized apparatus to establish a call between the two experimenters and enable them to converse, the apparatus being cut into the call in order to acquire data about the call. The experimenters' opinions are solicited concerning their perceptions of the quality level they observe during their conversation. The apparatus evaluates consistency of the data collected with the nominal experimental conditions and the nominal quality level associated with the current test. Then, a determination is made as to how the current test is to be carried out as a function of a test plan and of the result of the evaluation.

Abstract: The voice quality of telephone calls is evaluated. A first connection is established between a computerized apparatus and a person acting as a first experimenter, and a second connection is established between the platform and a second experimenter. The first and second connections are interconnected by the computerized apparatus to establish a call between the two experimenters and enable them to converse, the apparatus being cut into the call in order to acquire data about the call. The experimenters' opinions are solicited concerning their perceptions of the quality level they observe during their conversation. The apparatus evaluates consistency of the data collected with the nominal experimental conditions and the nominal quality level associated with the current test. Then, a determination is made as to how the current test is to be carried out as a function of a test plan and of the result of the evaluation.

Abstract: An equipment embodying the invention is designed for bit-level quality check of a digital link in the presence of real traffic. The equipment complies with CCITT recommendations and comprises two checking stations (SP, SS) respectively located at two ends of the digital link (LT) and connected to one another by a service link (LS). First and second check information relating respectively to groups of transmitted frames (MTn.sub.p) and to groups of received frames (MTn.sub.s) are calculated in the stations and comparisons are made in order to detect the transmission errors. The check informations and the frame groups concerned by the transmission errors are transmitted from one station to the other via the service link. Processing circuits are distributed among the stations thereby processing the frame groups concerned by the transmission errors, i.e., analyzing at bit level the errors in the erroneous frames and deriving statistical information and recordings relating to said errors.