Abstract: A speech processing apparatus includes a spectrum envelope extracting unit which extracts the spectrum envelope of an input speech signal, a spectrum envelope deforming unit which applies deformation to the spectrum envelope to generate a deformed spectrum envelope, a spectrum fine structure extracting unit which extracts the spectrum fine structure of the input speech signal, a deformed spectrum generating unit which generates a deformed spectrum by combining the deformed spectrum envelope with the spectrum fine structure, and a speech generating unit which generates an output speech signal on the basis of the deformed spectrum. This apparatus emits a disrupting sound based on the output speech signal to prevent a third party from eavesdropping on a conversation.

Abstract: A speech processing apparatus includes a spectrum envelope extracting unit which extracts the spectrum envelope of an input speech signal, a spectrum envelope deforming unit which applies deformation to the spectrum envelope to generate a deformed spectrum envelope, a spectrum fine structure extracting unit which extracts the spectrum fine structure of the input speech signal, a deformed spectrum generating unit which generates a deformed spectrum by combining the deformed spectrum envelope with the spectrum fine structure, and a speech generating unit which generates an output speech signal on the basis of the deformed spectrum. This apparatus emits a disrupting sound based on the output speech signal to prevent a third party from eavesdropping on a conversation.

Abstract: A post-filter includes a microphone array including at least two microphones to which a voice signal are input, a beam former which forms the voice signal input from the microphone array, a divider which divides a target sound containing noise input from the microphone array into at least two frequency bands at a predetermined frequency, a first filter which estimates the filter gain with the noise non-correlated between the microphones, a second filter which estimates a filter gain of one microphone of the microphone array or an average signal of the microphone array, an adder which adds the outputs from the first and second filters to each other, and a filter for reducing the noise based on the outputs from the adder and the beam former.