Subtraction of a shaped component of a noise reduction spectrum from a combined signal
AssigneeTexas Instruments Incorporated
InventorsFITZGERALD JOHN ARCHIBALD, KARTHIK SWAMINATHAN, ANIL KUMAR SIRIKANDE
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Abstract
A system and methods of subtraction of a shaped component of a noise reduction spectrum from a combined signal are disclosed. In an embodiment, a method includes identifying a selected frequency component using a corresponding frequency component of a noise sample spectrum. A noise set is comprised of the noise sample spectrum. The method further includes forming a shaped component of a noise reduction spectrum using a processor and a memory based on a combined signal spectrum and the selected frequency component. The method also includes subtracting the shaped component of the noise reduction spectrum from the combined signal spectrum.
Claims20
A method, comprising:
- identifying a selected frequency component using a corresponding frequency component of a noise sample spectrum, wherein a noise set is comprised of the noise sample spectrum;
- forming a shaped component of a noise reduction spectrum using a processor and a memory based on a combined signal spectrum and the selected frequency component;
- and
- subtracting the shaped component of the noise reduction spectrum from the combined signal spectrum.
A system, comprising:
- a noise spectrum estimator module to identify a selected frequency component using a corresponding frequency component of a noise sample spectrum, wherein a noise set is comprised of the noise sample spectrum;
- a noise spectrum shaping module to form a shaped component of a noise reduction spectrum using a processor and a memory based on a combined signal spectrum and the selected frequency component;
- and
- a spectral subtraction module to subtract the shaped component of the noise reduction spectrum from the combined signal spectrum.
A method, comprising:
- obtaining a noise sample spectrum using at least one of a prerecorded sample of a background noise and a locally characterized sample of the background noise;
- identifying a selected frequency component using a corresponding frequency component of a noise sample spectrum, wherein a noise set is comprised of the noise sample spectrum, and wherein the noise sample spectrum is obtained using at least one of a prerecorded sample of the background noise and a locally characterized sample of the background noise;
- algorithmically determining whether to use the selected frequency component to generate a shaped component of the noise reduction spectrum, wherein a threshold value is used to algorithmically determine whether to use the selected frequency component to generate a shaped component of the noise reduction spectrum, wherein the threshold value is comprised of a combined signal frequency component multiplied by an amplification factor;
- forming the shaped component of a noise reduction spectrum using a processor and a memory based on a combined signal spectrum and the selected frequency component, wherein the shaped component of a noise reduction spectrum is comprised of a largest corresponding frequency component of the noise set when the largest corresponding frequency component is less than the threshold value, and wherein the shaped component of a noise reduction spectrum is comprised of an average of corresponding frequency components of the noise set when the largest corresponding frequency component is greater than the threshold value;
- subtracting the shaped component of the noise reduction spectrum from the combined signal spectrum;
- reconstructing an adaptively filtered speech signal;
- and
- normalizing a signal level of a reconstructed speech signal.
Dependencies are inferred from the claim text.