US 2003/0120486 A1 · Speech recognition system and method

Abstract

A speech input stream is fed to a first speech recogniser. A confidence measure is formed for each recognition hypothesis produced in output by the first speech recogniser and this confidence measure is compared against an acceptability threshold. Where the confidence measure of a recognition hypothesis is below the threshold, the corresponding portion of the speech input is passed to a second speech recogniser and the recognition hypothesis produced is used instead of, or as a supplement to, that output by the first speech recogniser. In a preferred embodiment, the first speech recogniser is a recogniser trained to a particular user whilst the second recogniser is one associated with a particular speech application currently being accessed by the user.

Claims29

Dependent claims

A speech recognition method comprising the steps of:

(a) carrying out recognition of a speech input stream using a first speech recognizer to derive respective first recognition hypotheses for successive portions of the input stream;
(b) in carrying out step (a), determining a confidence measure for each first recognition hypothesis;
(c) at least in respect of those portions of the speech input stream for which the confidence measure is below an acceptability threshold, passing the speech input stream to a second speech recognizer to produce corresponding second recognition hypotheses;
and
(d) forming an output recognition-hypothesis stream using recognition hypotheses from the first recognition hypotheses and only those second recognition hypotheses corresponding to the first recognition hypotheses that have a confidence measure below said threshold.

2 more elements

A speech recognition system comprising:

a first speech recognizer for carrying out recognition of a speech input stream to derive respective first recognition hypotheses for successive portions of the input stream;
an acceptability-determination subsystem for deriving a confidence measure for each first recognition hypothesis and comparing this measure with an acceptability threshold to determine the acceptability of the recognition hypothesis;
a second speech recognizer for producing second recognition hypotheses for portions of the input stream;
a transfer arrangement for passing to the second speech recognizer at least those portions of the speech input stream for which the confidence measure is below said acceptability threshold;
and
a control arrangement for forming an output recognition-hypothesis stream using recognition hypotheses from the first recognition hypotheses and only those second recognition hypotheses corresponding to the first recognition hypotheses that have a confidence measure below said threshold.

3 more elements

Dependencies are inferred from the claim text.

Speech recognition system and method

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Speech recognition system and method

Life of this patent

Abstract

Claims29