Speech processing system

An apparatus for searching a database comprising a plurality of annotations which include annotation data and a quality measure indicative of the quality of an annotation used to generate the annotation data, the apparatus comprising:

• means for receiving an input audio query;
• means for determining a quality measure for the input audio query;
• and
• means for comparing data representative of said input query with the annotation data of one or more of said annotations in dependence upon the quality measure for said input query and the corresponding quality measure for the annotation.

A method of determining a quality measure indicative of the quality of a speech signal, the method comprising the steps of:

• receiving, at a receiver, a set of speech signal values representative of a speech signal generated by a speech source as distorted by a transmission channel between the speech source and the receiver;
• storing a predetermined function which includes a first part having first parameters which models said source and a second part having second parameters which models said channel and which gives, for a given set of speech signal values, a probability density for parameters of a predetermined speech model which is assumed to have generated the set of speech 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 model is assumed to have generated the set of speech signal values;
• applying the set of received speech signal values to said stored function to give the probability density for said model parameters for the set of received speech signal values;
• processing said function with said set of received speech signal values applied, to derive samples of at least said first parameters from said probability density;
• analysing at least some of said derived samples of said at least first parameters to determine a quality measure indicative of the quality of the received speech signal values;
• and
• outputting values of said first parameters that are representative of said speech signal generated by said speech source before it was distorted by said transmission channel.

A method of searching a database comprising a plurality of annotations which include annotation data and a quality measure indicative of the quality of an annotation used to generate the annotation data, the method comprising the steps of:

• receiving an input audio query;
• determining a quality measure for the input audio query;
• and
• comparing data representative of said input query with the annotation data of one or more of said annotations in dependence upon the quality measure for said input query and the corresponding quality measure for the annotation.

An apparatus for determining a quality measure indicative of the quality of a speech signal, the apparatus comprising:

• means for receiving a set of speech signal values representative of a speech signal generated by a speech source as distorted by a transmission channel between the speech source and the receiving means;
• a memory for storing a predetermined function which includes a first part having first parameters which models said source and a second part having second parameters which models said channel and which gives, for a given set of speech signal values, a probability density for parameters of a predetermined speech model which is assumed to have generated the set of speech 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 model is assumed to have generated the set of speech signal values;
• means for applying the set of received speech signal values to said stored function to give the probability density for said model parameters for the set of received speech signal values;
• means for processing said function with said set of received speech signal values applied, to derive samples of at least said first parameters from said probability density;
• means for analysing at least some of said derived samples of said at least first parameters to determine a quality measure indicative of the quality of the received speech signal values;
• and
• means for outputting values of said first parameters that are representative of said speech signal generated by said speech source before it was distorted by said transmission channel.