Multimodal code-excited linear prediction (CELP) coder and method using peakiness measure

A method of encoding speech, comprising the steps of:

• getting a gain value from an input speech;
• obtaining a target vector from the input speech;
• gain normalizing the target vector;
• and
• determining an optimal excitation vector by minimizing an error between the gain normalized target vector and a synthesis-filtered excitation vector.

A method of encoding speech, comprising the steps of:

• getting a gain value from an input speech;
• gain normalizing the input speech;
• obtaining a target vector from the gain normalized input speech;
• determining an optimal excitation vector by minimizing an error between the target vector of the gain normalizing input speech and a synthesis-filtered excitation vector.

A method of classifying speech, comprising the steps of:

• receiving a speech input;
• getting a first value by computing the p-th root of the sum of the p-th powers of the absolute values of the components of the speech input vector;
• getting a second value by computing the n-th root of the sum of the n-th powers of the absolute values of the components of the speech input vector;
• getting a peakiness measure of the speech input by dividing said first value by said second value;
• determining if the peakiness measure is greater than a peakiness threshold;
• and
• if the peakiness measure is greater than the peakiness threshold, classifying the speech input in a first mode of a multimodal speech coder including a code-excited linear prediction mode.

A code-excited linear prediction (CELP) coder, comprising:

• an encoder operable to receive a speech input;
• a peakiness module in communication with the encoder;
• the peakiness module operable to get a peakiness measure of the speech input where said peakiness measure is independent of pitch lag and to determine if the peakiness measure is greater than a peakiness threshold;
• the encoder operable to classify the speech input in a first mode where the peakiness measure is greater than the peakiness threshold;
• and
• the encoder operable to encode first mode input speech with a pulse excitation system.