Patent ID: 8538746

Claim:
A method of providing a quality measure for an output voice signal generated to reproduce an input voice signal, the method comprising: partitioning the input voice signal and the output voice signal into frames; for each frame in the input voice signal, determining frame disturbance for a plurality of frames of the input voice signal which correspond to an utterance in the input voice signal, relative to a corresponding utterance in the output voice signal; performing an initial dynamic time warp and determining which frame disturbances are to be used as a subset for calculating a MOS quality measure for the output voice signal; wherein determining which frame disturbances are to be used, comprises: calculating a grid having intersecting nodes representing magnitude of frame disturbance between an output voice frame and an input voice frame; calculating a path on said grid which provides an improved time alignment; for at least one node of said intersecting nodes, replacing one or more frames in the input voice signal and/or the output voice signal with one or more new frames that generate a plurality of new nodes in a vicinity of said one node that have smaller pitch than nodes generated by original frames; performing an additional dynamic time warp on each one of said plurality of new nodes; and based on the determination of which frame disturbances are to be used, calculating the MOS quality measure for the output voice signal.