Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Nec Solution Innovators, Ltd.

Ikuo Kajiyama

Shinya Takahashi

Bunkei Matsuoka

Hirohisa Tasaki

Jou Akitomi

Atsuyoshi Yano

Koichi Shiraki

Miho Ishii

The continual engagement support deviceincludes: the performance data storage meansthat stores performance data including time data indicating the time of performance and sensor data of the time of performance or the surrounding time obtained from the sensors mounted on the portable terminal when the target action is performed via the portable terminal possessed by the target user; the timing detection meansthat detects the performance timing, which is the timing at which the target user is likely to perform the target action during the predetermined cycle, on the basis of the performance data; and the notification meansprovides a notification to prompt the performance of the target action at the detected performance timing when the target action is not performed for a predetermined period of time or longer.

Continual engagement support device, portable terminal, continual engagement support method, and program

A state deciding unitmakes a decision of double talk when both received signal and transmission signal are in a speech burst, and when the amount of reduction in an echo removal level per prescribed time period exceeds a predetermined threshold, the echo removal level being represented as a level difference between the transmission signal and a residual signal passing through the echo elimination by an adaptive filter, and when the amount of changes of the signal level of the received signal is less than a prescribed reference value.

Echo canceler

An echo canceller has a high-pass filtera speakeran A/D converterand an echo canceller. The high-pass filtersuppresses a low-frequency component in a received signal. The speakeroutputs an acoustic sound of a low-frequency suppressed received signal passed through the high-pass filterThe A/D converterconverts an acoustic echo from a microphoneinto a transmission signal of a digital form. The echo cancellergenerates a pseudo echo signal based on the low-frequency suppressed received signal passed through the high-pass filterand eliminates the acoustic echo to be inputted to the microphonefrom the speakerby subtracting the pseudo echo signal from the digital signal converted by the A/D converter

Echo processing apparatus

The renewal of a group of first tap coefficients is controlled according to a reception signal, a transmission signal and a first error signal. In contrast, the renewal of a group of second tap coefficients is controlled according to only the reception signal. An echo canceled output signal is produced from the group of first tap coefficients in cases where an estimate precision of the group of first tap coefficients is higher than that of the group of second tap coefficients, and an echo canceled output signal is produced from the group of second tap coefficients in cases of the before-initial estimate, the echo path change and the infinite return loss. Accordingly, the echo canceled output signal, in which the echo is canceled, can be reliably produced regardless of the echo path change or the infinite return loss.

Echo canceling apparatus

A first pseudo-echo signal approximating an echo of a reception signal superposed on a transmission signal is produced from a delayed reception signal corresponding to a past time according to filer coefficients, and a first residual signal is produced from the first pseudo-echo signal and a delayed transmission signal. Also, the filer coefficients are renewed to reduce the first residual signal. Therefore, when a single-talk state based on a far-end caller's voice of the reception signal is changed to a double-talk state by adding a near-end caller' voice to the transmission signal, the first filter coefficients deteriorate. Also, a second pseudo-echo signal is produced from a reception signal currently received according to the first filter coefficients renewed. Because a time difference exists between the signals corresponding to the renewal of the first filter coefficients and the production of the second pseudo-echo signal, a deterioration factor is indicated in a delayed second residual signal produced from the second pseudo-echo signal, so that the double-talk state can be detected according to a difference between the first residual signal and the delayed second residual signal.

Double-talk detecting apparatus, echo canceller using the double-talk detecting apparatus and echo suppressor using the double-talk detecting apparatus

An echo canceller which estimates an echo gain from a reception signal level and a transmission signal level; calculates logarithmically converted power of a reception signal level; calculates logarithmically converted power of a transmission signal level; estimates an echo gain based on the reception signal level and the transmission signal level; adds the estimated echo gain to the reception signal level to obtain an estimated echo level, calculates logarithmically converted power of a residual signal level; and compares the estimated echo level with the residual signal level after echo cancellation; wherein the echo of the reception signal contained in the transmission signal is canceled when the estimated echo level exceeds the value obtained by adding a margin to the residual signal level.

Growing community of inventors

Tokyo, Japan

Ikuo Kajiyama