1. A method for estimating automatic speech recognition (ASR) accuracy, the method comprising: obtaining transcriptions of utterances in a conversation over two channels; sorting the transcriptions along a time axis using a forced alignment; training a language model with the sorted transcriptions; performing ASR for utterances in a conversation between a first user and a second user, the second user being a target of ASR accuracy estimation; determining whether an ASR result of the second user is consistent or inconsistent with an ASR result of the first user using the trained language model; listing word sequences that have at least one word from the first user followed by a word from the second user; and estimating the ASR result of the second user as poor responsive to the ASR result of the second user being as inconsistent with the ASR result of the first user.