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

A technology of suppressing device and level, which is applied to electrical components, transducer acoustic response prevention, hearing aids, etc., can solve the problems of processing sound quality deterioration and erroneous adaptation, and achieve the effect of reducing sound quality deterioration and suppressing howling.

Inactive Publication Date: 2011-01-05
PANASONIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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.

Method used

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

Examples

Experimental program
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Effect test

Embodiment approach 1

[0041] figure 1 It is a block diagram of the howling suppressing device 100 according to Embodiment 1 of the present invention.

[0042] The howling suppression device 100 is provided with: an input terminal 101, which inputs a signal from a microphone not shown in the figure; an A / D converter 102, which performs A / D conversion of a signal input to the input terminal 101 from an analog signal to a digital signal; a delayer 103 , the signal output from the A / D converter 102 is delayed to generate a reference signal of the adaptive filter 109 described later; the signal separation unit 104 separates the signal output from the A / D converter 102 into periodic signal components and Non-periodic signal components; the howling detection unit 105 uses the output signal of the signal separation unit 104 to detect the occurrence of howling; the howling suppression unit 106 suppresses the howling according to the howling detection result of the howling detection unit 105 D / A converter ...

Embodiment approach 2

[0075] Figure 5 It is a block diagram showing the configuration of the howling detection unit 105 in the howling suppression device 100 according to Embodiment 2 of the present invention. In addition, in Figure 5 in, for with figure 2 The same symbols are used for the same structural elements and descriptions are omitted.

[0076] exist Figure 5 Among them, the howling detecting unit 105 according to the second embodiment includes: a level change analyzing unit 301 which analyzes the temporal change of the signal level calculated by the level calculating unit 203; Based on the analysis result of the variation analysis unit 301, it is judged whether or not a howling has occurred.

[0077] Next, the operation of the howling suppression device 100 according to the second embodiment will be described.

[0078] In the level change analysis unit 301 , the difference value between the past and the present value of the signal level of the periodic signal component output from...

Embodiment approach 3

[0084] Figure 6 It is a block diagram showing the configuration of the howling detection unit 105 of the howling suppression device 100 according to Embodiment 3 of the present invention. In addition, in Figure 6 in, right with figure 2 The same symbols are used for the same structural elements and descriptions are omitted.

[0085] exist Figure 6 Among them, the howling detection unit 105 according to Embodiment 3 includes: a frequency band division unit 401 which divides a signal of a periodic signal component input to the input terminal 201 into a plurality of frequency band signals; The signal levels of the plurality of frequency band signals output by the division unit 401 ; and the howling determination unit 403 , using the signal levels of the plurality of frequency band signals calculated by the frequency band level calculation unit 402 , to determine whether or not howling has occurred.

[0086] Next, the operation of the howling suppression device 100 accordi...

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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 ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04R3/02
CPCH04R25/453H04R3/02
Inventor 浦威史
Owner PANASONIC CORP
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