Invention Grant
- Patent Title: Apparatus for removing howling and method for removing howling
-
Application No.: US15485434Application Date: 2017-04-12
-
Publication No.: US09848261B2Publication Date: 2017-12-19
- Inventor: Junji Araki , Hiromasa Ohashi , Naoya Tanaka
- Applicant: Panasonic Intellectual Property Management Co., Ltd.
- Applicant Address: JP Osaka
- Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
- Current Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
- Current Assignee Address: JP Osaka
- Agency: Wenderoth, Lind & Ponack, L.L.P.
- Priority: JP2014-212213 20141017
- Main IPC: H04B15/00
- IPC: H04B15/00 ; H04R3/02 ; H04R3/04

Abstract:
A howling removing apparatus according to the present disclosure is a howling removing apparatus to be connected to a microphone and a speaker. The howling removing apparatus includes: a nonlinear converter that nonlinearly converts a sound signal input to the speaker and outputs a nonlinear signal; a delay unit that delays the sound signal by a fixed time and outputs a delay signal; a norm calculator that calculates a norm from the delay signal; a filter coefficient generator that, based on the nonlinear signal, the delay signal and the norm, generates an adaptive filter that simulates a transfer characteristic of a space where the sound signal is reproduced from the speaker and is returned to the microphone; a cancel signal generator that convolves the delay signal and the adaptive filter with each other and generates a cancel signal; and a subtracter that subtracts the cancel signal from the sound signal. When an average sound pressure level of the sound signal exceeds a threshold value, the filter coefficient generator initializes the adaptive filter, thereby sensing oscillation of the adaptive filter even when a positional relationship between the microphone and the speaker is dynamically changed, and returning an output to normal.
Public/Granted literature
- US20170223454A1 APPARATUS FOR REMOVING HOWLING AND METHOD FOR REMOVING HOWLING Public/Granted day:2017-08-03
Information query