Patent ID: 7412375

Claim:
An apparatus for assessing the perceptual quality of speech signals transmitted via a telecommunications network and recorded acoustically from an acoustic terminal device comprising: a front end processor for aligning a mono reference signal comprising a single channel with a degraded stereo signal comprising a first channel and a second channel, said front end processor comprising a leveller for adjusting the power levels of said signals and a time aligner for determining the estimated delays for each of said channels of said degraded signal; an auditory transformer for generating a set of perceptually relevant parameters for each of said signals; and a comparator for comparing said perceptually relevant parameters to generate disturbance profiles; and a modeller for generating a speech quality prediction in dependence upon said disturbance profiles; in which said front end processor further comprises a noise masking determiner for comparing signal parameters of each of said channels of said degraded signal and generating a noise masking indicator in dependence upon said parameters; and in which said disturbance profiles are dependent upon said noise masking indicator.