Signal processing method and apparatus, and recording medium in which a signal processing program is recorded

• US 8,804,980 B2
• Filed: 10/14/2011
• Issued: 08/12/2014
• Est. Priority Date: 03/06/2007
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Sugiyama, Akihiko, Kato, Masanori
• Primary Examiner(s): Paul, Disler
• Application Number:
  US13/273,322
• Publication Number:
  US 20120033828A1
• Time in Patent Office: 1,033 Days
• Field of Search: 381 941- 944, 381/94.7, 704/226, 704/233
• US Class Current: 381/94.3
• CPC Class Codes: G10L 19/265 Pre-filtering, e.g. high frequency emphasis prior to encoding
• CPC Class Codes: G10L 21/0208 Noise filtering

Abstract

A signal processing method for converting a signal received via a transmission path or read from a storage medium into a first audible signal, and suppressing a noise other than a desired signal contained in the first audible signal based on predetermined audio quality adjustment information, comprising steps of: in suppressing a noise other than a desired signal contained in the first audible signal to generate an enhanced signal, receiving audio quality adjustment information for adjusting audio quality; and adjusting audio quality of the enhanced signal using the audio quality adjustment information.

Claims

1. A signal processing method for converting a signal received via a transmission path or read from a storage medium into a first audible signal, and suppressing a noise other than a desired signal contained in said first audible signal based on predetermined audio quality adjustment information, comprising steps of:

in suppressing a noise other than a desired signal contained in said first audible signal to generate an enhanced signal, receiving audio quality adjustment information for adjusting audio quality; and

adjusting audio quality of said enhanced signal using said audio quality adjustment information,

wherein said noise is suppressed by;

converting an input signal into a frequency-domain signal;

obtaining an estimated noise using said frequency-domain signal;

determining a suppression coefficient using said estimated noise and said frequency-domain signal;

correcting said suppression coefficient to obtain a corrected suppression coefficient so that distortion is reduced in a likely-to-be-voiced segment and a residual noise is reduced in a likely-to-be-non-voiced segment, said corrected suppression coefficient being obtained by;

obtaining a ratio of an average power in said likely-to-be-voiced segment to an average power in said likely-to-be-non-voiced segment; and

obtaining said corrected suppression coefficient so that said residual noise in said likely-to-be-non-voiced segment is reduced when said ratio has a larger value; and

weighting said frequency-domain signal with said corrected suppression coefficient.

2. A signal processing apparatus comprising:

a receiver for converting a signal received via a transmission path or read from a storage medium into a first audible signal; and

a noise suppressor for suppressing a noise other than a desired signal contained in said first audible signal using predetermined audio quality adjustment information,

wherein, in suppressing a noise other than a desired signal contained in said first audible signal to generate an enhanced signal, said noise suppressor receives audio quality adjustment information for adjusting audio quality, and adjusts audio quality of said enhanced signal using said audio quality adjustment information,

wherein said noise suppressor comprises;

a converter for converting an input signal into a frequency-domain signal;

a noise estimator for estimating a noise using said frequency-domain signal;

a noise suppression coefficient generator for determining a suppression coefficient using said estimated noise and said frequency-domain signal;

a suppression coefficient corrector for obtaining a corrected suppression coefficient using said estimated noise, said frequency-domain signal and said suppression coefficient; and

a multiplier for weighting said frequency-domain signal with said corrected suppression coefficient, and

said suppression coefficient corrector corrects said suppression coefficient so that distortion is reduced in a likely-to-be-voiced segment and a residual noise is reduced in a likely-to-be-non-voiced segment, said suppression coefficient corrector obtaining a ratio of an average power in said likely-to-be-voiced segment to an average power in said likely-to-be-non-voiced segment, and corrects said suppression coefficient so that a residual noise in said likely-to-be-non-voiced segment is reduced when said ratio has a larger value.