Acoustic signal processing device and acoustic signal processing method

Patent metadata

Field	Value
Publication number	US-9280986-B2
Application number	US-201314381989-A
Country	US
Kind code	B2
Filing date	Jan 23, 2013
Priority date	Mar 12, 2012
Publication date	Mar 8, 2016
Grant date	Mar 8, 2016

Abstract

Provided is an acoustic signal processing device for producing an output sound meeting listener's preferences by adjusting attack sound, reverberation, and noise component. The device includes: an FFT section for transforming an input audio signal from a time-domain to a frequency-domain to calculate a frequency spectrum signal and for generating a first amplitude spectrum signal and a phase spectrum signal; an attack component controller ( 10 ) for controlling an attack component of the first amplitude spectrum signal to generate a second amplitude spectrum signal; a reverberation component controller ( 20 ) for controlling a reverberation component of the first amplitude spectrum signal to generate a third amplitude spectrum signal; a first adding section ( 40 ) for synthesizing the first amplitude spectrum signal, the second amplitude spectrum signal, and the third amplitude spectrum signal to generate a fourth amplitude spectrum signal; and an IFFT section for generating an audio signal transformed from a frequency domain to a time domain based on the fourth amplitude spectrum signal and the phase spectrum signal generated by the FFT section.

First claim

The invention claimed is:

1. An acoustic signal processing device comprising:
an FFT section in which a short-time Fourier transform to an input audio signal is performed with time shifted by a differential time between a Fourier transform length and an overlap length to transform the input audio signal from a time-domain signal into a frequency-domain signal and to calculate a frequency spectrum signal, and a first amplitude spectrum signal and a phase spectrum signal are generated based on the frequency spectrum signal;
an attack component controller provided for controlling an attack component of the first amplitude spectrum signal generated by the FFT section to generate a second amplitude spectrum signal;
a reverberation component controller provided for controlling a reverberation component of the first amplitude spectrum signal generated by the FFT section to generate a third amplitude spectrum signal;
a first adding section provided for synthesizing the first amplitude spectrum signal generated by the FFT section, the second amplitude spectrum signal generated by the attack component controller, and the third amplitude spectrum signal generated by the reverberation component controller to generate a fourth amplitude spectrum signal; and
an IFFT section provided for calculating a frequency spectrum signal based on the fourth amplitude spectrum signal generated by the first adding section and the phase spectrum signal generated by the FFT section and applying an inverse short-time Fourier transform and an overlap addition to the calculated frequency spectrum signal to generate an audio signal transformed from a frequency domain to a time domain, wherein
the attack component controller comprises:
a first HPF section for applying, on a per spectrum basis, high-pass filtering to the first amplitude spectrum signal generated by the FFT section based on a preset first cut-off frequency;
a first limiter section for limiting a negative side amplitude of the amplitude spectrum signal that has been subjected to the high-pass filtering by the first HPF section to set the negative side amplitude to 0 to detect, on a per spectrum basis, the attack component of the amplitude spectrum signal; and
a first gain section for applying, based on a preset first weighting amount, weighting processing to the attack component of the amplitude spectrum signal detected by the first limiter section,
the reverberation component controller comprises:
a second HPF section for applying, on a per spectrum basis, high-pass filtering to the first amplitude spectrum signal generated by the FFT section based on a preset second cut-off frequency;
an amplitude inverting section for multiplying the amplitude spectrum signal that has been subjected to the high-pass filtering by the second HPF section by −1 to invert an amplitude of the amplitude spectrum signal;
a second limiter section for limiting a negative side amplitude of the amplitude spectrum signal that has been subjected to the amplitude inversion by the amplitude inverting section to set the negative side amplitude to 0 to detect, on a per spectrum basis, the reverberation component of the amplitude spectrum signal; and
a second gain section for applying, based on a preset second weighting amount, weighting processing to the reverberation component of the amplitude spectrum signal detected by the second limiter section.

2. The acoustic signal processing device according to claim 1 , further comprising a noise controller for performing noise control of the fourth amplitude spectrum signal generated by the first adding section to generate a fifth amplitude spectrum signal, wherein
the IFFT section generates the audio signal transformed from a frequency domain to a time domain based on the fifth amplitude spectrum signal generated by the noise controller and the phase spectrum signal generated by the FFT section, and
the noise controller comprises:
a third HPF section for applying, on a per spectrum basis, high-pass filtering to the fourth amplitude spectrum signal generated by the first adding section based on a preset third cut-off frequency;
a third limiter section for limiting a negative side amplitude of the amplitude spectrum signal that has been subjected to the high-pass filtering by the third HPF section to set the negative side amplitude to 0;
a third gain section for applying, based on a preset third weighting amount which is a value equal to or more than 0 and equal to or less than 1, weighting processing to the amplitude spectrum signal whose negative side amplitude has been limited by the third limiter section;
a fourth gain section for applying, based on a weighting amount obtained by subtracting a value of the third weighting amount from a value of 1, weighting processing to the fourth amplitude spectrum signal generated by the first adding section; and
a second adding section for synthesizing the amplitude spectrum signal that has been subjected to the weighting processing by the third gain section and the amplitude spectrum signal that has been subjected to the weighting processing by the fourth gain section to generate the fifth amplitude spectrum signal.

3. An acoustic signal processing method for an acoustic signal processing device in which an attack component control and a reverberation component control are applied to an input audio signal,
the acoustic signal processing device comprising:
an FFT section for transforming the input audio signal from a time-domain signal into a frequency-domain signal to calculate a frequency spectrum signal and for generating a first amplitude spectrum signal and a phase spectrum signal;
an attack component controller for controlling an attack component of the first amplitude spectrum signal generated by the FFT section to generate a second amplitude spectrum signal;
a reverberation component controller for controlling a reverberation component of the first amplitude spectrum signal generated by the FFT section to generate a third amplitude spectrum signal;
a first adding section for synthesizing the first amplitude spectrum signal generated by the FFT section, the second amplitude spectrum signal generated by the attack component controller, and the third amplitude spectrum signal generated by the reverberation component controller to generate a fourth amplitude spectrum signal; and
an IFFT section for generating an audio signal transformed from a frequency domain to a time domain based on the fourth amplitude spectrum signal generated by the first adding section and the phase spectrum signal generated by the FFT section,
the attack component controller including:
a first HPF section, a first limiter section, and a first gain section,
the reverberation component controller including:
a second HPF section, an amplitude inverting section, a second limiter section, and a second gain section,
wherein the acoustic signal processing method, comprising the steps of:
performing a short-time Fourier transform to the input audio signal with time shifted by a differential time between a Fourier transform length and an overlap length to calculate the frequency spectrum signal, and generating the first amplitude spectrum signal and the phase spectrum signal based on the frequency spectrum signal, in the FFT section;
applying, on a per spectrum basis, high-pass filtering to the first amplitude spectrum signal generated by the FFT section based on a preset first cut-off frequency by means of the first HPF section of the attack component controller;
limiting a negative side amplitude of the amplitude spectrum signal that has been subjected to the high-pass filtering by the first HPF section to set the negative side amplitude to 0 to detect, on a per spectrum basis, the attack component of the amplitude spectrum signal by means of the first limiter section of

Assignees

• Clarion Co Ltd

Inventors

• Hashimoto Takeshi
• Watanabe Tetsuo

Classifications

• G10L21/02

  Speech enhancement, e.g. noise reduction or echo cancellation (reducing echo effects in line transmission systems H04B3/20; echo suppression in hands-free telephones H04M9/08) · CPC title

• H04R3/04

  for correcting frequency response · CPC title

• H04R2227/007

  Electronic adaptation of audio signals to reverberation of the listening space for PA · CPC title

• G10L21/057 Primary

  for improving intelligibility · CPC title

• G10K11/175 Primary

  using interference effects; Masking sound · CPC title