Title:
Howling erasing device and howling erasing method
Document Type and Number:
Japanese Patent JP6314325
Kind Code:
B2
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.
Inventors:
Junji Araki
Hiromasa Ohashi
Naoya Tanaka
Hiromasa Ohashi
Naoya Tanaka
Application Number:
JP2016553967A
Publication Date:
April 25, 2018
Filing Date:
October 09, 2015
Export Citation:
Assignee:
Panasonic IP Management Co., Ltd.
International Classes:
H04R3/02
Domestic Patent References:
| JP4428247B2 | ||||
| JP7254870A | ||||
| JP4130835B2 |
Foreign References:
| WO2012120815A1 |
Attorney, Agent or Firm:
Kenji Kamada
Hiroo Maeda
Hiroo Maeda