Method and system for reducing effects of noise producing artifacts in a speech signal

A speech decoding system for reducing effect of noise producing artifacts in silence areas of a speech signal, the speech decoding system comprising:

• a digital-to-analog converter (DAC);
• wherein the speech decoding system is configured to:
• obtain a plurality of incoming samples representative of a speech subframe;
• sum an energy level for each of the plurality of samples to generate a total input level;
• determine whether the speech subframe is in a silence area using the total input level;
• set a gain value as a function of the total input level in response to determining that the speech subframe is in the silence area, wherein the function results in the gain value increasing as the total input value increases and the gain value decreasing as the total input value decreases;
• multiply the plurality of samples representative of the speech subframe by the gain value to produce modified samples;
• and
• generate a digital speech signal using the modified samples;
• wherein the DAC is configured to convert the digital speech signal into an analog signal.

A method of reducing effect of noise producing artifacts in silence areas of a speech signal for use by a speech decoding system, the method comprising:

• obtaining a plurality of incoming samples of a speech subframe;
• summing an absolute value of an energy level for each of the plurality of incoming samples to generate a total input level (gain_in);
• smoothing the total input level to generate a smoothed level (Level_in_sm);
• determining whether the speech subframe is in a silence area based on the total input level, the smoothed level and the first reflection coefficient (parcor0), using:
• (Level _in _sm<1024) && (gain_in<2*Level _in_sm)&& (parcor0 <512/32768);
• defining a gain in response to determining that the speech subframe is in the silence area;
• modifying an energy level of the speech subframe using the gain to produce a modified speech subframe;
• generating a digital speech signal using the modified speech subframe;
• and
• converting, using a digital-to-analog converter (DAC), the digital speech signal into an analog signal.

A speech decoding system for reducing effect of noise producing artifacts in silence areas of a speech signal, the speech decoding system comprising:

• a digital-to-analog converter (DAC);
• wherein the speech decoding system is configured to:
• obtain a plurality of incoming samples of a speech subframe;
• sum an absolute value of an energy level for each of the plurality of incoming samples to generate a total input level (gain_in);
• smooth the total input level to generate a smoothed level (Level_in_sm);
• determine whether the speech subframe is in a silence area based on the total input level, the smoothed level and the first reflection coefficient (parcor0), using:
• (Level_in_sm<1024) && (gain_in<2*Level_in_sm)&& (parcor0<512/32768);
• define a gain in response to determining that the speech subframe is in the silence area;
• modify an energy level of the speech subframe using the gain to produce a modified speech subframe;
• and
• generate a digital speech signal using the modified speech subframe;
• wherein the DAC is configured to convert the digital speech signal into an analog signal.

A method of reducing effect of noise producing artifacts in silence areas of a speech signal for use by a speech decoding system, the method comprising:

• obtaining a plurality of incoming samples of a speech subframe;
• summing an absolute value of an energy level for each of the plurality of incoming samples to generate a total input level (gain_in);
• smoothing the total input level to generate a smoothed level (Level_in_sm);
• determining that the speech subframe is in a silence area based on the total input level, the smoothed level and a spectral tilt parameter;
• defining a gain using k1*(Level_in_sm/1024)+(1-k1 ), where k1 is a function of the spectral tilt parameter;
• modifying an energy level of the speech subframe using the gain to produce a modified speech subframe;
• generating a digital speech signal using the modified speech subframe;
• and
• converting, using a digital-to-analog converter (DAC), the digital speech signal into an analog signal.

A speech decoding system for reducing effect of noise producing artifacts in silence areas of a speech signal, the speech decoding system comprising:

• a subframe energy level calculator configured to obtain a plurality of incoming samples of a speech subframe, and configured to sum an absolute value of an energy level for each of the plurality of incoming samples to generate a total input level (gain_in), and further configured to smooth the total input level to generate a smoothed level (Level_in_sm);
• a subframe energy level comparator configured to determine that the speech subframe is in a silence area based on the total input level, the smoothed level and a spectral tilt parameter;
• a subframe energy level modifier configured to define a gain using k1*(Level_in_sm/1024)+(1-k1), where k1 is a function of the spectral tilt parameter, and further configured to modify an energy level of the speech subframe using the gain to produce a modified speech subframe;
• an output for generating a digital speech signal using the modified speech subframe;
• and
• a digital-to-analog converter configured to convert the digital speech signal into an analog signal.