Speech processing system

A method of detecting the presence of speech within an input audio signal, comprising:

• storing a predetermined function which gives, for a given set of audio signal values, a probability density for parameters of a predetermined speech model which is assumed to have generated the set of audio signal values, the probability density defining, for a given set of model parameter values, the probability that the predetermined speech model has those parameter values, given that the speech model is assumed to have generated the set of audio signal values;
• receiving a set of audio signal values representative of an input audio signal at a receiver;
• applying the set of received audio signal values to said stored function to give the probability density for said model parameters for the set of received audio signal values;
• processing said function with said set of received audio signal values applied to obtain values of said parameters that are representative of said input audio signal;
• and
• detecting the presence of speech using said obtained parameter values.

An apparatus for detecting the presence of speech within an input audio signal, comprising:

• a memory operable to store a predetermined function which gives, for a given set of audio signal values, a probability density for parameters of a predetermined speech model which is assumed to have generated the set of audio signal values, the probability density defining, for a given set of model parameter values, the probability that the predetermined speech model has those parameter values, given that the speech model is assumed to have generated the set of audio signal values;
• a receiver operable to receive a set of audio signal values representative of an input audio signal;
• an applicator operable to apply the set of received audio signal values to said stored function to give the probability density for said model parameters for the set of received audio signal values;
• a processor operable to process said function with said set of received audio signal values applied to obtain values of said parameters that are representative of said input audio signal;
• and
• a detector operable to detect the presence of speech using said obtained parameter values.

A speech recognition system comprising:

• a receiver operable to receive an input signal representative of an audio signal;
• a memory operable to store a predetermined function which gives, for a given set of audio signal values, a probability density for parameters of a predetermined speech model which is assumed to have generated the set of audio signal values, the probability density defining, for a given set of model parameter values, the probability that the predetermined speech model has those parameter values, given that the speech model is assumed to have generated the set of audio signal values;
• an applicator operable to apply a set of audio signal values representative of the input signal to said stored function to give the probability density for said model parameters for the set of audio signal values;
• a processor operable to process said function with said set of audio signal values applied to obtain values of said parameters that are representative of said input signal;
• a detector operable to detect the presence of speech using said obtained parameter values;
• and
• a recognition processor operable to perform a recognition processing of the portion of the input signal corresponding to speech.

A speech processing system comprising:

• a receiver operable to receive an input audio signal;
• a memory operable to store a predetennined function which gives, for a given set of audio signal values, a probability density for parameters of a predetermined speech model which is assumed to have generated the set of audio signal values, the probability density defining, for a given set of model parameter values, the probability that the predetermined speech model has those parameter values, given that the speech model is assumed to have generated the set of audio signal values;
• an applicator operable to apply a set of audio signal values representative of the input audio signal to said stored function to give the probability density for said model parameters for the set of audio signal values;
• a first processor operable to process said function with said set of audio signal values applied to obtain values of said parameters that are representative of said input audio signal;
• a detector operable to detect the presence of speech using said obtained parameter values;
• and
• a second processor operable to process the portion of the input audio signal corresponding to speech.

A computer readable medium storing computer executable instructions for causing a programmable computer device to carry out a method of detecting the presence of speech within an input audio signal, the instructions comprising instructions for:

• storing a predetermined function which gives, for a given set of audio signal values, a probability density for parameters of a predetermined speech model which is assumed to have generated the set of audio signal values, the probability density defining, for a given set of model parameter values, the probability that the predetermined speech model has those parameter values, given that the speech model is assumed to have generated the set of audio signal values;
• receiving a set of audio signal values representative of an input audio signal at a receiver;
• applying the set of received audio signal values to said stored function to give the probability density for said model parameters for the set of received audio signal values;
• processing said function with said set of received audio signal values applied to obtain values of said parameters that are representative of said input audio signal;
• and
• detecting the presence of speech using said obtained parameter values.