Abstract: Methods, including computer programs encoded on a computer storage medium, for improving speech recognition based on external data sources. In one aspect, a method includes obtaining an initial candidate transcription of an utterance using an automated speech recognizer and identifying, based on a language model that is not used by the automated speech recognizer in generating the initial candidate transcription, one or more terms that are phonetically similar to one or more terms that do occur in the initial candidate transcription. Additional actions include generating one or more additional candidate transcriptions based on the identified one or more terms and selecting a transcription from among the candidate transcriptions.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining pronunciations for particular terms. The methods, systems, and apparatus include actions of obtaining audio samples of speech corresponding to a particular term and obtaining candidate pronunciations for the particular term. Further actions include generating, for each candidate pronunciation for the particular term and audio sample of speech corresponding to the particular term, a score reflecting a level of similarity between of the candidate pronunciation and the audio sample, wherein the said score for the particular term is obtained by using a minimum of individual scores of phonemes comprising the term. Additional actions include aggregating the scores for each candidate pronunciation and adding one or more candidate pronunciations for the particular term to a pronunciation lexicon based on the aggregated scores for the candidate pronunciations.

Abstract: Methods, including computer programs encoded on a computer storage medium, for improving speech recognition based on external data sources. In one aspect, a method includes obtaining an initial candidate transcription of an utterance using an automated speech recognizer and identifying, based on a language model that is not used by the automated speech recognizer in generating the initial candidate transcription, one or more terms that are phonetically similar to one or more terms that do occur in the initial candidate transcription. Additional actions include generating one or more additional candidate transcriptions based on the identified one or more terms and selecting a transcription from among the candidate transcriptions.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for discovery of problematic pronunciations for automatic speech recognition systems. One of the methods includes determining a frequency of occurrences of one or more n-grams in transcribed text and a frequency of occurrences of the n-grams in typed text and classifying a system pronunciation of a word included in the n-grams as correct or incorrect based on the frequencies. The n-grams may comprise one or more words and at least one of the words is classified as incorrect based on the frequencies. The frequencies of the specific n-grams may be determined across a domain using one or more n-grams that typically appear adjacent to the specific n-grams.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining pronunciations for particular terms. The methods, systems, and apparatus include actions of obtaining audio samples of speech corresponding to a particular term and obtaining candidate pronunciations for the particular term. Further actions include generating, for each candidate pronunciation for the particular term and audio sample of speech corresponding to the particular term, a score reflecting a level of similarity between of the candidate pronunciation and the audio sample. Additional actions include aggregating the scores for each candidate pronunciation and adding one or more candidate pronunciations for the particular term to a pronunciation lexicon based on the aggregated scores for the candidate pronunciations.