Method for packet loss and/or frame erasure concealment in a voice communication system

A method for decoding an encoded speech signal, comprising:

• if a segment of the encoded speech signal is good, decoding the segment to derive an excitation signal and predictive parameters for controlling a synthesis filter;
• if the segment is bad, scaling a random sequence of samples to derive the excitation signal, and deriving the predictive parameters based on parameters associated with a previously-decoded segment;
• and
• filtering the excitation signal in a synthesis filter under the control of the predictive parameters.

A method for decoding an encoded speech signal, comprising:

• if a segment of the encoded speech signal is good, decoding the segment to derive an excitation signal;
• if the segment is bad, scaling a random sequence of samples to derive the excitation signal;
• and
• filtering the excitation signal in a synthesis filter under the control of predictive parameters.

A speech decoder, comprising:

• a controller configured to derive an excitation signal, long-term predictive parameters and short-term predictive parameters;
• a long-term synthesis filter that filters the excitation signal under the control of the long-term predictive parameters to generate a first output signal;
• a short-term synthesis filter that filters the first output signal under the control of the short-term predictive parameters to generate a second output signal;
• wherein the controller is configured to derive the excitation signal, long-term predictive parameters and short-term predictive parameters from decoded information pertaining to a segment of an encoded speech signal if the segment is good and to derive the excitation signal by scaling a random sequence of samples and derive the long-term predictive parameters and short-term predictive parameters based on parameters associated with a previously-decoded segment if the segment is bad.

A speech decoder, comprising:

• a controller configured to derive an excitation signal and predictive parameters;
• and
• a synthesis filter that filters the excitation signal under the control of the predictive parameters;
• wherein the controller is configured to derive the excitation signal and predictive parameters from decoded information pertaining to a segment of an encoded speech signal if the segment is good and to derive the excitation signal by scaling a random sequence of samples and derive the predictive parameters based on parameters associated with a previously-decoded segment if the segment is bad.

A speech decoder, comprising:

• a controller that derives an excitation signal;
• and
• a synthesis filter that filters the excitation signal under the control of predictive parameters;
• wherein the controller is configured to derive the excitation signal from decoded information pertaining to a segment of an encoded speech signal if the segment is good and to derive the excitation signal by scaling a random sequence of samples if the segment is bad.

A method for processing a speech signal, comprising:

• if a segment of the speech signal is good, using decoded information associated with the segment to derive an excitation signal, long-term predictive parameters and short-term predictive parameters
• if the segment is bad, scaling a random sequence of samples to derive the excitation signal and deriving the long-term predictive parameters and short-term predictive parameters based on parameters associated with a previously-processed segment of the speech signal;
• filtering the excitation signal in a long-term synthesis filter under the control of the long-term predictive parameters, thereby generating a first output signal;
• and
• filtering the first output signal in a short-term synthesis filter under the control of the short-term predictive parameters, thereby generating a second output signal.

A method for processing a speech signal, comprising:

• if a segment of the speech signal is good, using decoded information associated with the segment to derive an excitation signal and predictive parameters for controlling a synthesis filter;
• if the segment is bad, scaling a random sequence of samples to derive the excitation signal, and deriving the predictive parameters based on parameters associated with a previously-processed segment;
• and
• filtering the excitation signal in a synthesis filter under the control of the predictive parameters.

A method for processing a speech signal, comprising:

• if a segment of the speech signal is good, using decoded information associated with the segment to derive an excitation signal;
• if the segment is bad, scaling a random sequence of samples to derive the excitation signal;
• and
• filtering the excitation signal in a synthesis filter under the control of predictive parameters.