Fast out-of-vocabulary search in automatic speech recognition systems

A system comprising a computer system comprising a processor, memory, and storage, the system being configured to:

• receive a text search query, the query comprising one or more query words;
• generate, for each query word in the query, a set of one or more anchor segments from searching metadata corresponding to a plurality of speech recognition processed audio files, the metadata including representations of one or more words detected in the audio files, wherein, for each detected word, the metadata includes a reference to each audio file in which the word was detected, a temporal location of the detected word in the audio file, and a confidence measure for the word as detected within the audio file, where each anchor segment includes a query word, an identifier for an audio file, and a temporal location of the query word within the audio file, where generating anchor segments includes, for each query word, the computer system:
• determining if the query word is included in a vocabulary of a learning model for a speech recognizer engine of the computer system;
• when the query word is in the vocabulary, searching the metadata to identify one or more high confidence anchor segments corresponding to the query word;
• and
• when the query word is not in the vocabulary:
• generating a search list of one or more sub-words of the query word,
• searching the metadata to identify one or more audio files containing at least one of the one or more sub-words to identify one or more anchor segments corresponding to one or more of the sub-words;
• post-process the one or more anchor segments, the post-process comprising:
• expanding the one or more anchor segments;
• sorting the one or more anchor segments;
• and
• merging overlapping ones of the one or more anchor segments;
• and
• perform speech recognition on the post-processed one or more expanded anchor segments for instances of at least one of the one or more query words using a constrained grammar.

A system comprising

• means for receiving a text search query, the query comprising one or more query words;
• means for generating, for each query word in the query, a set of one or more anchor segments from searching metadata corresponding to a plurality of speech recognition processed audio files, the metadata including representations of one or more words detected in the audio files, wherein, for each detected word, the metadata includes a reference to each audio file in which the word was detected, a temporal location of the detected word in the audio file, and a confidence measure for the word as detected within the audio file, where each anchor segment includes a query word, an identifier for an audio file, and a temporal location of the query word within the audio file, where the means for generating anchor segments includes, for each query word:
• means for determining if the query word is included in a vocabulary of a learning model for a speech recognizer engine of the computer system;
• when the query word is in the vocabulary, means for searching the metadata to identify one or more high confidence anchor segments corresponding to the query word;
• and
• means for, when the query word is not in the vocabulary:
• generating a search list of one or more sub-words of the query word,
• searching the metadata to identify one or more audio files containing at least one of the one or more sub-words to identify one or more anchor segments corresponding to one or more of the sub-words;
• means for post-processing the one or more anchor segments comprising:
• means for expanding the one or more anchor segments;
• means for sorting the one or more anchor segments;
• and
• means for merging overlapping ones of the one or more anchor segments;
• and
• means for searching the post-processed one or more expanded anchor segments for instances of at least one of the one or more query words using a constrained grammar.