1. An apparatus for verifying an utterance in a speech recognition system, the apparatus comprising: a noise processor configured to process noise of an input speech signal; a feature extractor configured to extract features of speech data obtained through the noise processing; an event detector configured to detect events of the plurality of speech features occurring in the speech data using the noise-processed data and data of the extracted features; a decoder configured to perform speech recognition using a plurality of preset speech recognition models for the extracted feature data; and an utterance verifier configured to calculate confidence measurement values in units of words and sentences using information on the plurality of events detected by the event detector and a preset utterance verification model, and perform utterance verification according to the calculated confidence measurement values, wherein the utterance verification model includes a smoothing anti-model, a specific anti-model, a filler model, and a support vector machine (SVM) model.
4. The apparatus of claim 1 , wherein the utterance verification model further includes: a word-level utterance verifier configured to separately calculate word-specific confidence scores of words of sections in which the events have occurred and words for which no event has occurred; a sentence-level utterance verifier configured to calculate confidence scores in units of sentences or utterance based on the word-specific confidence scores calculated by the word-level utterance verifier; a sentence-level event application utterance verifier configured to calculate sentence-specific confidence scores to which the events are applied without separating words from each other using section information of the sections in which the events have occurred and estimated values of a plurality of feature parameters; a sentence structure and meaning analyzer configured to analyze sentence structures and meanings of speech recognition result sentences which are search results of the decoder, and calculate confidence scores of sentences; and a decision maker configured to compare the scores calculated by the sentence-level utterance verifier, the scores calculated by the sentence-level event application utterance verifier, and the scores calculated by the sentence structure and meaning analyzer with a preset threshold value and determine whether or not to accept the speech recognition result sentences according to comparison results.