Abstract: It is possible to accurately estimate the echo suppression amount for each frequency even when a nonlinear echo component is large. An estimated echo function having variables of a logarithm of a magnitude at each frequency of a reception signal, a frequency of the reception signal, a logarithm of a total reception value that is a summation of magnitudes of the reception signal or transmission of the reception signal in any frequency range, and a logarithm of an envelope of the total reception value is stored. An echo suppressing process is performed by inputting a value of a second reception signal (a result of converting the reception signal into a frequency domain) to a function representing an estimated echo to generate an echo suppressing mask, and multiplying an echo suppressing gain calculated based on this echo suppressing mask by a second transmission signal (transmission signal converted into a frequency domain).

Abstract: A non-linear echo is allowed to be suppressed and voice deterioration is allowed to be suppressed. An echo suppression device for suppressing an echo generated by inputting a voice signal output from a speaker to a microphone includes a compressor on a receiving signal path for transmitting a signal of a receiving signal to the speaker. When a double-talk state has been detected, the compressor performs a compression process on a signal greater than a first threshold among the receiving signals.

Abstract: Even when a speech is small, the speech is allowed to be detected and an echo is allowed to be appropriately suppressed. Whenever a sample point of a reception signal transmitted through a receiving signal path that transmits a signal to a speaker is acquired, an optimal mask is sequentially generated or selected from base masks as one or a plurality of masks generated based on a learning signal based on a reception signal acquired within a predetermined period before a time point at which the sample point was acquired. Whenever the optimal mask is selected, whether a double-talk state is present is sequentially detected based on a result of comparing an input signal with the optimal mask. When detecting that a speech is not input to a microphone and the reception signal includes a speech, a process of suppressing an echo is sequentially performed on the input signal.

Abstract: An echo is allowed to be effectively removed while a processing load on an arithmetic device is reduced. When a magnitude of a reference signal transmitted to a speaker is equal to or greater than a first threshold, a learning algorithm using nonlinear processing is selected. When the magnitude of the reference signal is smaller than the first threshold, a learning algorithm using linear processing is selected. The echo is learnt using the selected learning algorithm to remove an echo included in an input signal picked up by a microphone based on a learning result.

Abstract: A non-linear echo is allowed to be suppressed and voice deterioration is allowed to be suppressed. An echo suppression device for suppressing an echo generated by inputting a voice signal output from a speaker to a microphone includes a compressor on a receiving signal path for transmitting a signal of a receiving signal to the speaker. When a double-talk state has been detected, the compressor performs a compression process on a signal greater than a first threshold among the receiving signals.

Abstract: An echo is allowed to be effectively removed while a processing load on an arithmetic device is reduced. When a magnitude of a reference signal transmitted to a speaker is equal to or greater than a first threshold, a learning algorithm using nonlinear processing is selected. When the magnitude of the reference signal is smaller than the first threshold, a learning algorithm using linear processing is selected. The echo is learnt using the selected learning algorithm to remove an echo included in an input signal picked up by a microphone based on a learning result.

Abstract: A double-talk state can be accurately detected, and based on a detection result, echo can be appropriately suppressed. When a sound is output from a speaker and only the output sound is input to a microphone, a comparison is made, for each of different frequency bands, between a frequency mask generated based on a power spectrum or an amplitude spectrum for a learning signal transmitted through a transmitting signal path and a value of a power spectrum or an amplitude spectrum for an input signal input from the microphone, to detect whether there is a double-talk state. In a case of detecting that no signal is being transmitted through the transmitting signal path and that a signal is being transmitted through the receiving signal path, an echo suppressor is used to execute processing of suppressing an echo in the input signal.

Abstract: A double-talk state can be accurately detected, and based on a detection result, echo can be appropriately suppressed. When a sound is output from a speaker and only the output sound is input to a microphone, a comparison is made, for each of different frequency bands, between a frequency mask generated based on a power spectrum or an amplitude spectrum for a learning signal transmitted through a transmitting signal path and a value of a power spectrum or an amplitude spectrum for an input signal input from the microphone, to detect whether there is a double-talk state. In a case of detecting that no signal is being transmitted through the transmitting signal path and that a signal is being transmitted through the receiving signal path, an echo suppressor is used to execute processing of suppressing an echo in the input signal.

Abstract: There is provided an echo suppression device that allows adding a natural comfort noise even in an environment in which a change in ambient noise is large. An echo is removed from an input signal to generate an echo-removed signal, a noise signal included in the echo-removed signal is estimated to generate an estimated noise signal, and a noise signal included in the echo-removed signal is suppressed based on the estimated noise signal to generate a suppressed signal. A comfort noise is generated based on the estimated noise signal, and the comfort noise is superimposed on the suppressed signal.