SOUND SIGNAL PROCESSING DEVICE AND SOUND SIGNAL PROCESSING METHOD

PROBLEM TO BE SOLVED: To provide a sound signal processing method and a sound signal processing device carrying out processing with respect to an input signal including deteriorated sound such as quantization noise such that the deteriorated sound can be hardly heard subjectively. SOLUTION: After the spectrum of a decoded sound which is an input sound is auditorily weighted, the spectrum is calculated by a deformation strength control unit, and the deformation strength is calculated based on the amplitude and continuity of the spectrum. The spectrum of the decoded sound is obtained by a signal deformation unit. Then the amplitude is smoothed, phase disturbance is imparted in accordance with the deformation strength, and the decoded sound is returned to a signal region as a deformed decoded sound. The decoded sound is analyzed, and the background noise likeness is calculated by a signal evaluating unit and used as an addition control value. If the addition control value shows the background noise likeness in a weighted value adder, the weight for adding to the decoded speech is reduced, the weight for adding to the transformed decoded speech is increased, and an output speech is obtained. COPYRIGHT: (C)2010,JPO&INPIT