Speech recognition apparatus, speech recognition method, and computer-readable recording medium

A speech recognition method comprising the steps of:

• (a) selecting, from learning texts for a plurality of fields for generating language models for the fields, a phrase that includes a word whose appearance frequency satisfies a set condition on a field-by-field basis, and generating an identification language model for identifying the field of input speech using the selected phrases;
• (b) executing speech recognition on the input speech using the identification language model, and outputting text data and a confidence for each word included in the text data as a recognition result;
• and
• (c) specifying a field that includes the most words whose confidences are greater than or equal to a set value based on the text data, the confidences of the words, and the words included in the learning texts for the fields, and determining that the specified field is the field of the input speech.

A computer-readable recording medium having recorded thereon a program containing instructions for causing a computer to execute the following steps:

• (a) selecting, from learning texts for a plurality of fields for generating language models for the fields, a phrase that includes a word whose appearance frequency satisfies a set condition on a field-by-field basis, and generating an identification language model for identifying the field of input speech using the selected phrases;
• (b) executing speech recognition on the input speech using the identification language model, and outputting text data and a confidence for each word included in the text data as a recognition result;
• and
• (c) specifying a field that includes the most words whose confidences are greater than or equal to a set value based on the text data, the confidences of the words, and the words included in the learning texts for the fields, and determining that the specified field is the field of the input speech.