Rion Company Ltd.

Iwate University

Inter-University Research Institute Corporation Research Organization of Information and Systems

National University Corporation, Iwate University

Masahiro Sunohara

Nobuhiko Hiruma

Chiho Haruta

Nobutaka Ono

Makoto Tateno

Kiyoshi Nishiyama

Kazuteru Nishiyama

Yoko Fujishima

Mariko Nakaichi

Masatoshi Osawa

Yoichi Fujisaka

A system identification device for performing fast real-time identification for a system from input/output data includes a filter robust to disturbance, by setting the maximum energy gain from the disturbance to a filter error, as an evaluation criterion, smaller than a given upper limit. The filter estimates a state estimation value of a state of the system.

System identification device, system identification method, system identification program, and recording medium recording system identification program

Provided is a hearing aid including a receiver, a microphone, an adaptive filter estimating a feedback transfer function from the receiver to the microphone, a subtractor, a hearing aid processor, a first whitening filter, a second whitening filter having a whitening filter coefficient identical to that of the first whitening filter, a coefficient updater, and a controller controlling the adaptive filter and the first and second whitening filters. The controller updates and saves, as a stabilization coefficient, the coefficient of the adaptive filter in a condition in which the autocorrelation of the first signal is low, determines the presence or absence of a change in the feedback transfer function based on the coefficient of the adaptive filter and the stabilization coefficient, and performs, when it is determined that the feedback transfer function has changed, the control in order that effectiveness of whitening by the first and second whitening filters is reduced as compared to that when it is determined that the feedback transfer function does not change.

Feedback canceller and hearing aid

A dereverberation device includes an input instantaneous value calculation unit configured to calculate an input instantaneous value based on an input signal; a reverberation estimation unit configured to calculate a moving average of the input instantaneous value as a reverberation component; a gain calculation unit configured to calculate, with the input instantaneous value and the reverberation component, a first gain as a basic gain for the input signal; a gain suppression control unit configured to calculate, according to a ratio between the input instantaneous value and the reverberation component, a second gain changing within a range between a predetermined lower limit and a predetermined upper limit, thereby outputting a larger one of the first gain or the second gain as a third gain; and a gain processing unit configured to multiply the input signal by the third gain.

Dereverberation device and hearing aid

A sound source separation apparatus includes: a separation-matrix processor that transforms a plurality of observation signals corresponding to sounds being propagated from a plurality of sound sources into a frequency-domain signal group the separation-matrix processor updating a separation matrix based on the frequency-domain signal group and transforming the updated separation matrix into time-series filter coefficients to output; a filter-coefficient transformer that partially removes non-causal components from the filter coefficients to transform the filter coefficients, and a separator that supplies the filter coefficients to a filter group, the separator generating a plurality of separation signals separated from the plurality of observation signals corresponding to the separation matrix.

Sound source separation apparatus

A reverberation suppression apparatus includes: an instantaneous value calculation unit that calculates an instantaneous value/instantaneous values in an envelope of values correlating with the absolute value or the square of an input signal; a reverberation estimation unit that calculates an exponential moving average of the instantaneous value(s) as an estimated reverberation component; a gain derivation unit that derives a gain corresponding to the input signal according to the estimated reverberation component and the instantaneous value(s) when the each instantaneous value is larger than the estimated reverberation component, and derives a lower limit of the gain as the gain corresponding to the input signal when the each instantaneous value is smaller than the estimated reverberation component; a smoothing unit that performs a smoothing process on the gain; and a gain processing unit that applies the gain to amplitude adjustment of the input signal thereafter.

Reverberation suppression apparatus used for auditory device

A hearing aid according to an embodiment of the present disclosure includes: a microphone configured to convert sound into an electric signal and output a first signal; a receiver configured to convert the third signal that is generated by performing predetermined hearing aid processing on a second signal, into sound; a first feedback removal unit having an adaptive filter configured to adaptively estimate a first transfer function of a sound feedback path from the receiver to the microphone; and a second feedback removal unit having a fixed filter configured to receive the third signal and use a fixed filter coefficient based on a second transfer function of a vibration feedback path from the receiver to the microphone. The second signal is generated by removing from the first signal, output signals from the adaptive filter and the fixed filter.

Hearing aid and feedback canceller

A hearing aid includes: a microphone; a hearing aid processing unit configured to provide a gain to a first signal based on an output signal from the microphone to generate a second signal; a receiver configured to convert the second signal into sound; an adaptive filter configured to adaptively estimate a transfer function corresponding to a pathway from an input side of the receiver to an output side of the microphone; and a feedback removal unit configured to subtract a third signal generated based on the transfer function from the output signal of the microphone to obtain a signal and output the signal as the first signal; and a control unit configured to control the gain setting unit and an adaptive speed of the adaptive filter.

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Tokyo, Japan

Masahiro Sunohara