Method and apparatus for training speech recognition algorithms for directory assistance applications
First Claim
1. A method for performing a telephone directory assistance function, comprising:
- for each of a plurality of callers;
prompting the caller to speak a name associated with a desired directory listing;
determining a telephone number desired by the caller based on a speech signal received from the caller subsequent to the step of prompting the caller;
releasing the desired telephone number to the caller; and
creating a call record comprising the released telephone number and a representation of the speech signal;
processing according to a parameter modification algorithm a plurality of the call records to modify parameters of a speech recognition algorithm; and
employing the speech recognition algorithm to recognize names spoken by callers in directory assistance calls received subsequent to modification of the parameters of the speech recognition algorithm.
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Accused Products
Abstract
In methods and apparatus for at least partially automating a telephone directory assistance function, directory assistance callers are prompted to speak locality or called entity names associated with desired directory listings. A speech recognition algorithm is applied to speech signals received in response to prompting to determine spoken locality or called entity names. Desired telephone numbers are released to callers, and released telephone numbers are used to confirm or correct at least some of the recognized locality or called entity names. Speech signal representations labelled with the confirmed or corrected names are used as labelled speech tokens to refine prior training of the speech recognition algorithm. The training refinement automatically adjusts for deficiencies in prior training of the speech recognition algorithm and to long term changes in the speech patterns of directory assistance callers served by a particular directory assistance installation. The methods can be generalized to other speech recognition applications.
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Citations
31 Claims
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1. A method for performing a telephone directory assistance function, comprising:
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for each of a plurality of callers; prompting the caller to speak a name associated with a desired directory listing; determining a telephone number desired by the caller based on a speech signal received from the caller subsequent to the step of prompting the caller; releasing the desired telephone number to the caller; and creating a call record comprising the released telephone number and a representation of the speech signal; processing according to a parameter modification algorithm a plurality of the call records to modify parameters of a speech recognition algorithm; and employing the speech recognition algorithm to recognize names spoken by callers in directory assistance calls received subsequent to modification of the parameters of the speech recognition algorithm.
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2. A method for performing a telephone directory assistance function, comprising:
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for each of a plurality of callers; prompting the caller to speak a name associated with a desired directory listing; receiving a speech signal from the caller; applying a speech recognition algorithm to the received speech signal to recognize a name in a name vocabulary as corresponding to the received speech signal; determining a telephone number desired by the caller using the recognized name; releasing the desired telephone number to the caller; and creating a call record comprising the released telephone number and a stored representation of the speech signal to associate the stored representation of the speech signal with the released telephone number; processing according to a parameter modification algorithm a plurality of the call records to modify parameters of the speech recognition algorithm, said processing comprising; processing each of the call records by; deriving a plurality of name candidates from the released telephone number; for each name candidate, calculating a measure of probability that the name candidate corresponds to the stored representation of the speech signal; identifying a best name candidate having the highest measure of probability of the plurality of name candidates; applying acceptance criteria based on the calculated measures of probability and, in response to the acceptance criteria being met, creating a training record comprising the stored representation of the speech signal and the best candidate name; and processing the training records according to a training algorithm to modify the parameters of the speech recognition algorithm by, for each name of the name vocabulary; accumulating statistics for said name derived from plural training records containing said name as a best name candidate; and recalculating parameters associated with said name by the speech recognition algorithm from the statistics accumulated for said name; and employing the speech recognition algorithm to recognize names spoken by callers in directory assistance calls received subsequent to modification of the parameters of the speech recognition algorithm. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method for performing a telephone directory assistance function, comprising:
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for each of a plurality of calls, each call being made by a respective caller from a respective terminal having a respective telephone number; receiving a signal from an originating switch serving the respective terminal, the signal designating the telephone number of the respective terminal; prompting the caller to speak a name associated with a desired directory listing; determining a telephone number desired by the caller based on a speech signal received from the caller subsequent to the step of prompting the caller; releasing the desired telephone number to the caller; and creating a call record comprising the released telephone number and the telephone number of the respective terminal; processing according to a parameter modification algorithm a plurality of the call records to modify parameters of a speech recognition algorithm, said processing comprising calculating model parameters for a plurality of a-priori probability models, each a-priori probability model representing an estimated probability of a respective name in a name vocabulary being spoken during a directory assistance call as a function of the telephone number of the terminal from which the directory assistance call is placed; and employing the speech recognition algorithm to recognize names spoken by callers in directory assistance calls received subsequent to modification of the parameters of the speech recognition algorithm. - View Dependent Claims (18, 19)
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20. Apparatus for performing a telephone directory assistance function, comprising:
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a first processor for processing directory assistance calls, the first processor being operable to prompt callers to speak names associated with desired directory listings, to store in respective call records representations of speech signals received from the callers in response to the prompting, to execute a speech recognition algorithm to associate each stored representation of a speech signal with a respective name in a name vocabulary, and to record in the call records released telephone numbers received from a directory assistance database to associate the stored representations of the speech signals with respective ones of the released telephone numbers; and a second processor for processing the call records created by the first processor, the second processor being operable to process the call records to modify parameters of the speech recognition algorithm. - View Dependent Claims (21, 22)
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23. Apparatus for performing a telephone directory assistance function, comprising:
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a first processor for processing directory assistance calls, the first processor being operable for each of a plurality of directory assistance calls to prompt a respective caller to speak a name associated with a desired directory listing, to store in a respective call record a representation of a speech signal received from the caller in response to the prompting, to execute a speech recognition algorithm to calculate respective measures of probability that the speech signal received from the caller corresponds to each of a plurality of names in a name vocabulary, and to record in the call record a respective released telephone number received from a directory assistance database to associate the stored representation of the speech signal with the released telephone number; and a second processor for processing the call records created by the first processor, the second processor being operable to process the call records to modify parameters of the speech recognition algorithm and to download to memory accessible by the first processor the parameters of the speech recognition algorithm which have been modified according to the training algorithm. - View Dependent Claims (24)
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25. Apparatus for performing a telephone directory assistance function, comprising:
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a first processor for processing directory assistance calls, the first processor being operable to prompt callers to speak names associated with desired directory listings, to store in call records representations of speech signals received from the callers in response to the prompting, to execute a speech recognition algorithm to associate each stored representation of a speech signal with a respective name in a name vocabulary, to receive released telephone numbers from the directory assistance database and to record in the call records the released telephone numbers to associate the stored representations of the speech signals with respective ones of the released telephone numbers; and a second processor for processing the call records created by the first processor, the second processor being operable to process the call records to modify parameters of the speech recognition algorithm, said processing comprising calculating further measures of probability that the stored representation of the speech signal in each of the call records corresponds to the released name in that call record.
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26. Apparatus for performing a telephone directory assistance function, comprising:
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a first processor for processing directory assistance calls, the first processor being operable to prompt callers to speak names associated with desired directory listings, to store in call records representations of speech signals received from the callers in response to the prompting, to execute a speech recognition algorithm to associate each stored representation of a speech signal with a respective name in a name vocabulary, to receive released telephone numbers from the directory assistance database, to store a call placement time in each of the call records; and
to record in the call records the released telephone numbers to associate the stored representations of the speech signals with respective ones of the released telephone numbers; anda second processor for processing the call records created by the first processor, the second processor being operable to process the call records to modify parameters of the speech recognition algorithm based on the call placement times stored in the call records.
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27. Apparatus for performing a telephone directory assistance function, comprising:
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a first processor for processing directory assistance calls, the first processor being operable to prompt callers to speak names associated with desired directory listings, to store in call records representations of speech signals received from the callers in response to the prompting, to execute a speech recognition algorithm to associate each stored representation of a speech signal with a respective name in a name vocabulary, to receive released telephone numbers from a directory assistance database, and to record in the call records the released telephone numbers to associate the stored representations of the speech signals with respective ones of the released telephone numbers; a second processor for processing the call records created by the first processor, the second processor being operable to process the call records to modify parameters of the speech recognition algorithm; a first memory for storing a first set of instructions for execution by the first processor, the call records and a first set of the parameters of the speech recognition algorithm, the call records being read-accessible and the first set of the parameters of the speech recognition algorithm being write-accessible by the second processor; and a second memory for storing a second set of instructions for execution by the second processor, a database containing telephone numbers and corresponding names and a second set of the parameters of the speech recognition algorithm, said database being read-accessible by the second processor to derive name candidates from the released telephone numbers. - View Dependent Claims (28, 29, 30, 31)
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Specification