摘要:
In an echo suppression apparatus, an adaptive filter estimates an echo path of a near end, and generates a pseudo echo signal of a reception signal received from a far end. A subtractor subtracts the pseudo echo signal from a near-end signal including an echo signal of the reception signal, a near-end sound and a background noise, thereby generating an echo-canceled signal. A background noise estimation unit estimates a spectrum of the background noise. A non-linear processing unit performs spectrum subtraction of the estimated spectrum of the background noise from the spectrum of the echo-canceled signal, and controls a gain of the spectrum of the echo-canceled signal in response to the result of the spectrum subtraction, thereby obtaining a spectrum of a transmission signal transmitted to the far end. A threshold calculation unit calculates a threshold value used to determine presence or absence of the residual echo in the echo-canceled signal. The non-linear processing unit compares the result of the spectrum subtraction with the threshold value, then controls the spectrum of the echo-canceled signal with a high gain in case that the result of the spectrum subtraction is higher than the threshold value, and with a low gain in case that the result of the spectrum subtraction is not higher than the threshold value.
摘要:
A musical tone signal is synthesized based on performance information to simulate a sound generated from a musical instrument having a string and a body that supports the string by a support. There is provided a closed loop circuit having a delay element that simulates delay characteristic of vibration propagated through the string and a characteristic control element that simulates a variation in amplitude or frequency. A string model calculation circuit inputs an excitation signal based on the performance information to the closed loop circuit, and calculates first information representing a force of the string acting on the support based on a cyclic signal generated in the closed loop and representing the vibration of the string circuit. A body model calculation circuit calculates second information representing a displacement of the body or a derivative of the displacement. A musical tone signal calculation circuit calculates the musical tone signal.
摘要:
In a noise suppression device, an audio detector detects presence or absence of audio in an input signal. A first noise spectrum estimator estimates a noise spectrum contained in the input signal based on the input signal and detection result of the audio detector. A second noise spectrum estimator estimates the noise spectrum based on the input signal regardless of the detection result of the audio detector. A noise spectrum calculator calculates a final noise spectrum estimation value according to a length of detecting time during which the audio detector continuously detects the audio and based on first and second noise spectrum estimation values that are obtained as estimation results by the first and second noise spectrum estimators. A gain calculator calculates a noise suppression gain based on the final noise spectrum estimation value. A noise suppressor suppresses noise contained in the input signal by applying the noise suppression gain to the input signal.
摘要:
A musical tone signal is synthesized based on performance information to simulate a sound generated from a musical instrument having a string and a body that supports the string by a support. There is provided a closed loop circuit having a delay element that simulates delay characteristic of vibration propagated through the string and a characteristic control element that simulates a variation in amplitude or frequency. A string model calculation circuit inputs an excitation signal based on the performance information to the closed loop circuit, and calculates first information representing a force of the string acting on the support based on a cyclic signal generated in the closed loop and representing the vibration of the string circuit. A body model calculation circuit calculates second information representing a displacement of the body or a derivative of the displacement. A musical tone signal calculation circuit calculates the musical tone signal.
摘要:
In a noise suppression device, an audio detector detects presence or absence of audio in an input signal. A first noise spectrum estimator estimates a noise spectrum contained in the input signal based on the input signal and detection result of the audio detector. A second noise spectrum estimator estimates the noise spectrum based on the input signal regardless of the detection result of the audio detector. A noise spectrum calculator calculates a final noise spectrum estimation value according to a length of detecting time during which the audio detector continuously detects the audio and based on first and second noise spectrum estimation values that are obtained as estimation results by the first and second noise spectrum estimators. A gain calculator calculates a noise suppression gain based on the final noise spectrum estimation value. A noise suppressor suppresses noise contained in the input signal by applying the noise suppression gain to the input signal.
摘要:
In an echo suppression apparatus, an adaptive filter estimates an echo path of a near end, and generates a pseudo echo signal of a reception signal received from a far end. A subtractor subtracts the pseudo echo signal from a near-end signal including an echo signal of the reception signal, a near-end sound and a background noise, thereby generating an echo-canceled signal. A background noise estimation unit estimates a spectrum of the background noise. A non-linear processing unit performs spectrum subtraction of the estimated spectrum of the background noise from the spectrum of the echo-canceled signal, and controls a gain of the spectrum of the echo-canceled signal in response to the result of the spectrum subtraction, thereby obtaining a spectrum of a transmission signal transmitted to the far end. A threshold calculation unit calculates a threshold value used to determine presence or absence of the residual echo in the echo-canceled signal. The non-linear processing unit compares the result of the spectrum subtraction with the threshold value, then controls the spectrum of the echo-canceled signal with a high gain in case that the result of the spectrum subtraction is higher than the threshold value, and with a low gain in case that the result of the spectrum subtraction is not higher than the threshold value.