Simple noise suppression model
First Claim
Patent Images
1. A method for suppressing background noise from a speech signal, said method comprising:
- obtaining an input speech signal;
performing linear predictive coding (LPC) analysis on said input speech signal to obtain a z-domain representation of said input speech signal;
computing a spectrum tilt and a noise-to-signal ratio (NSR) of said z-domain representation of said input speech signal;
obtaining a spectrum tilt of a background noise model;
applying a gain to reduce energy of said input speech signal when said NSR is high;
reducing a spectral valley energy of said input speech signal when said spectrum tilt of said input speech signal is close or equivalent to said spectrum tilt of said background noise model; and
applying an inverse filter to said input speech signal when said spectrum tilt of said input speech signal is not close to said spectrum tilt of said background noise model, wherein said inverse filter is an inverse of said z-domain representation of said background noise model.
5 Assignments
0 Petitions
Accused Products
Abstract
An approach for efficiently reducing background noise from speech signal in real-time applications is presented. A noisy input speech signal is processed through an inverse filter when the spectrum tilt of the input signal is not that of a pure background noise model the noisy input signal is also filtered in order to reduce the spectrum valley areas of the noisy input signal when the background noise is present.
-
Citations
18 Claims
-
1. A method for suppressing background noise from a speech signal, said method comprising:
-
obtaining an input speech signal;
performing linear predictive coding (LPC) analysis on said input speech signal to obtain a z-domain representation of said input speech signal;
computing a spectrum tilt and a noise-to-signal ratio (NSR) of said z-domain representation of said input speech signal;
obtaining a spectrum tilt of a background noise model;
applying a gain to reduce energy of said input speech signal when said NSR is high;
reducing a spectral valley energy of said input speech signal when said spectrum tilt of said input speech signal is close or equivalent to said spectrum tilt of said background noise model; and
applying an inverse filter to said input speech signal when said spectrum tilt of said input speech signal is not close to said spectrum tilt of said background noise model, wherein said inverse filter is an inverse of said z-domain representation of said background noise model. - View Dependent Claims (2, 3, 4, 13, 14)
-
-
5. A computer program product comprising:
-
a computer usable medium having computer readable program code embodied therein for suppressing background noise from a speech signal;
said computer readable program code configured to cause a computer to;
obtain an input speech signal;
perform linear predictive coding (LPC) analysis on said input speech signal to obtain a z-domain representation of said input speech signal;
compute a spectrum tilt and a noise-to-signal ratio (NSR) of said z-domain representation of said input signal;
obtain a spectrum tilt of a background noise model;
apply a gain to reduce energy of said input speech signal when said NSR is high;
reduce a spectral valley energy of said input speech signal when said spectrum tilt of said input speech signal is close or equivalent to said spectrum tilt of said background noise model; and
apply an inverse filter to said input speech signal when said spectrum tilt of said input speech signal is not close to said spectrum tilt of said background noise model, wherein said inverse filter is an inverse of said z-domain representation of said background noise model. - View Dependent Claims (6, 7, 8, 15, 16)
-
-
9. An apparatus for suppressing background noise from a speech signal, said apparatus comprising:
-
an object for receiving an input speech signal;
an object for performing linear predictive coding (LPC) analysis on said input speech signal to obtain a z-domain representation of said input speech signal;
an object for computing a spectrum tilt and a noise-to-signal ratio (NSR) of said z-domain representation of said input signal;
an object for obtaining a spectrum tilt of a background noise model;
an object for applying a gain to reduce energy of said input speech signal when said NSR is high;
an object for reducing a spectral valley energy of said input speech signal when said spectrum tilt of said input speech signal is close or equivalent to said spectrum tilt of said background noise model; and
an object for applying an inverse filter to said input speech signal when said spectrum tilt of said input speech signal is not close to said spectrum tilt of said background noise model, wherein said inverse filter is an inverse of the z-domain representation of said background noise model. - View Dependent Claims (10, 11, 12, 17, 18)
-
Specification