# US 12,183,328 B2 · Language model biasing system

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- Number: US 12,183,328 B2
- Document ID: US12183328B2
- Status: Granted
- Kind: B2
- Application number: 18/318,495
- Filed: 2023-05-16
- Published: 2023-09-14
- Granted: 2024-12-31
- Earliest claimed: 2017-02-14
- Assignees: Google Inc.
- Applicants: Google LLC
- Inventors: Petar Aleksic; Pedro J. Moreno Mengibar
- Web page: https://patentgrep.com/patent/US12183328B2

## CPC

- G10L 15/07: to the speaker
- G10L 15/1815: {Semantic context, e.g. disambiguation of the recognition hypotheses based on word meaning}
- G10L 15/187: Phonemic context, e.g. pronunciation rules, phonotactical constraints or phoneme n-grams
- G10L 15/197: Probabilistic grammars, e.g. word n-grams
- G10L 15/01: Assessment or evaluation of speech recognition systems
- G10L 15/30: Distributed recognition, e.g. in client-server systems, for mobile phones or network applications
- G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING

## Abstract

Methods, systems, and apparatus for receiving audio data corresponding to a user utterance and context data, identifying an initial set of one or more n-grams from the context data, generating an expanded set of one or more n-grams based on the initial set of n-grams, adjusting a language model based at least on the expanded set of n-grams, determining one or more speech recognition candidates for at least a portion of the user utterance using the adjusted language model, adjusting a score for a particular speech recognition candidate determined to be included in the expanded set of n-grams, determining a transcription of user utterance that includes at least one of the one or more speech recognition candidates, and providing the transcription of the user utterance for output.

## Claims

### Claim 1

A computer-implemented method when executed on data processing hardware that causes the data processing hardware to perform operations comprising:
receiving an initial set of n-grams, the initial set of n-grams designated by an application developer of an application, each n-gram of the initial set of n-grams comprises n adjacent letters, symbols, or words;
biasing, using the initial set of n-grams, a trained speech recognizer by modifying one or more parameters of a trained language model used by the trained speech recognizer, the one or more parameters modified to increase prediction probabilities associated with the trained speech recognizer recognizing n-grams in audio data that are included in the initial set of n-grams;
receiving audio data corresponding to an utterance detected by a user device associated with a user; and
processing, using the biased trained speech recognizer and the modified trained language model, the received audio data corresponding to the utterance to determine a transcription of the utterance that is biased toward the initial set of n-grams.

### Claim 2 (depends on 1)

The computer-implemented method of claim 1, wherein the initial set of n-grams are identified before the user speaks the utterance.

### Claim 3 (depends on 1)

The computer-implemented method of claim 1, wherein the operations further comprise:
receiving context data for the user device,
wherein receiving the initial set of n-grams comprises identifying the initial set of n-grams from the context data.

### Claim 4 (depends on 3)

The computer-implemented method of claim 3, wherein:
the context data comprises an application identifier associated with the application; and
identifying the initial set of n-grams comprises retrieving data indicating one or more words or phrases corresponding to the application identifier.

### Claim 5 (depends on 3)

The computer-implemented method of claim 3, wherein:
the context data comprises a dialog state identifier; and
identifying the initial set of n-grams comprises retrieving data indicating one or more words or phrases corresponding to the dialog state identifier.

### Claim 6 (depends on 3)

The computer-implemented method of claim 3, wherein the context data comprises data that indicates a topic corresponding to an interface provided to the user by the user device.

### Claim 7 (depends on 3)

The computer-implemented method of claim 3, wherein the context data comprises data indicating a task to be performed using an interface provided to the user by the user device.

### Claim 8 (depends on 3)

The computer-implemented method of claim 3, wherein identifying the initial set of n-grams from the context data comprises:
identifying a first set of one or more n-grams from the context data; and
generating an expanded set of one or more n-grams based at least on the first set of n-grams, the expanded set of n-grams comprising one or more n-grams that are different from the n-grams in the first set of n-grams.

### Claim 9 (depends on 1)

The computer-implemented method of claim 1, wherein the utterance is detected by the user device providing an interface to the user.

### Claim 10 (depends on 1)

The computer-implemented method of claim 1, wherein:
the data processing hardware resides on the user device; or
the data processing hardware resides on a server system in communication with the user device over a communication network.

### Claim 11

A system comprising:
data processing hardware; and
memory hardware in communication with the data processing hardware and storing instructions that, when executed on the data processing hardware, causes the data processing hardware to perform operations comprising:
receiving an initial set of n-grams, the initial set of n-grams designated by an application developer of an application, each n-gram of the initial set of n-grams comprises n adjacent letters, symbols, or words;
biasing, using the initial set of n-grams, a trained speech recognizer by modifying one or more parameters of a trained language model used by the trained speech recognizer, the one or more parameters modified to increase prediction probabilities associated with the trained speech recognizer recognizing n-grams in audio data that are included in the initial set of n-grams;
receiving audio data corresponding to an utterance detected by a user device associated with a user; and
processing, using the biased trained speech recognizer and the modified trained language model, the received audio data corresponding to the utterance to determine a transcription of the utterance that is biased toward the initial set of n-grams.

### Claim 12 (depends on 11)

The system of claim 11, wherein the initial set of n-grams are identified before the user speaks the utterance.

### Claim 13 (depends on 11)

The system of claim 11, wherein the operations further comprise:
receiving context data for the user device,
wherein receiving the initial set of n-grams comprises identifying the initial set of n-grams from the context data.

### Claim 14 (depends on 13)

The system of claim 13, wherein:
the context data comprises an application identifier associated with the application; and
identifying the initial set of n-grams comprises retrieving data indicating one or more words or phrases corresponding to the application identifier.

### Claim 15 (depends on 13)

The system of claim 13, wherein:
the context data comprises a dialog state identifier; and
identifying the initial set of n-grams comprises retrieving data indicating one or more words or phrases corresponding to the dialog state identifier.

### Claim 16 (depends on 13)

The system of claim 13, wherein the context data comprises data that indicates a topic corresponding to an interface provided to the user by the user device.

### Claim 17 (depends on 13)

The system of claim 13, wherein the context data comprises data indicating a task to be performed using an interface provided to the user by the user device.

### Claim 18 (depends on 13)

The system of claim 13, wherein identifying the initial set of n-grams from the context data comprises:
identifying a first set of one or more n-grams from the context data; and
generating an expanded set of one or more n-grams based at least on the first set of n-grams, the expanded set of n-grams comprising one or more n-grams that are different from the n-grams in the first set of n-grams.

### Claim 19 (depends on 13)

The system of claim 13, wherein the utterance is detected by the user device providing an interface to the user.

### Claim 20 (depends on 13)

The system of claim 13, wherein:
the data processing hardware resides on the user device; or
the data processing hardware resides on a server system in communication with the user device over a communication network.
