1. A similar word discrimination method for discriminating words that may be misrecognized because of their similarity, comprising the steps of: receiving voice data of input words; using a learning voice model to obtain a specified output that shows a level of correctness in response to the voice data of the input words; processing the output to establish a specified period in which the characteristic components of the input words are included in the output, when the output shows a level of correctness of a predetermined amount or greater; examining the characteristics of the voice data of said input words during the specified period; and discriminating between the input words and words that are similar to the input words on the basis of the examination.