Howling suppression device, howling suppression method, program, and integrated circuit

Abstract

A howling suppressing apparatus able to mitigate the deterioration of sound quality in processed sound that is caused by howling, even in an acoustic feedback loop environment. The howling suppressing apparatus is provided with: a delay device (103) which delays an input signal and outputs a reference signal; a signal separation unit (104) which includes an adaptive filter (109) that adaptively updates the filter coefficient and thereby extracts a periodic signal component from the reference signal; a howling detection unit (105) which uses at least the signal of the periodic signal component outputted from the adaptive filter (109) to detect whether howling has occurred; and a howling suppressing unit (106) which includes a suppressing filter (111) which acquires the filter coefficient from the adaptive filter (109) when howling has been detected by the howling detection unit (105) and extracts the periodic signal component from the reference signal based on that filter coefficient, and a subtracter (112) which subtracts the periodic signal component from the input signal to thereby output an error signal.

Description

technical field [0001] The present invention relates to a howling suppressing device for suppressing howling generated due to the acoustic coupling between the speaker and the microphone in an acoustic device having a microphone and a speaker. Background technique [0002] Generally, in an acoustic device having a microphone and a speaker, sound output from the speaker propagates and is input to the microphone, thereby forming an acoustic feedback loop, and howling may occur. [0003] Conventionally, as a howling suppression device for suppressing howling, it has been proposed to use an adaptive filter to extract a howling component contained in an input signal, and to subtract the extracted howling component from the input signal to suppress howling. scheme (for example, refer to Patent Document 1). [0004] Figure 12 It is a block diagram of a conventional howling suppression device 1000 described in Patent Document 1. FIG. Such as Figure 12 As shown, the conventional ...

AI Technical Summary

Problems solved by technology

However, when howling occurs, an acoustic feedback loop is formed, and if the howling is suppressed, the signal necessary for learning the filter coefficient of the adaptive filter 1003 also disappears.

If filter coefficient learning is continued in this state, there is a problem that erroneous adaptation is performed and the sound quality of the processed sound deteriorates.

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