Patent ID: 7366663

Claim:
A method for measuring talking quality of a telephone link in a telecommunications network, the method comprising the steps of: subjecting a degraded speech signal s′(t), with respect to a talker speech signal s(t) and to an objective measurement technique, so as to produce a quality signal (q), wherein the degraded speech signal comprises a returned signal r(t) corresponding to a signal occurring in a return channel of the telephone link during transmission of the talker speech signal in a forward channel of the telephone link, wherein the subjecting step comprises the steps of: generating, in response to the degraded speech signal, a first representation signal (R′(t,f)), the first representation signal representing a combination of the talker speech signal and the returned signal; generating, in response to the talker speech signal, a second representation signal (R(t,f)); and combining the first and second representation signals so as to produce the quality signal, wherein the combining step comprises the steps of: subtracting the first representation signal from the second representation signal so as to produce a difference signal (D(t,f)); producing an estimated value (Ne) of loudness of the noise present in the returned signal; suppressing noise in the difference signal through use of the estimated value (Ne) so as to produce a modified difference signal (D′(t,f)); and integrating the modified difference signal, with respect to frequency and time, so as to produce the quality signal.