1. An electronic device comprising: a memory configured to store a user pronunciation lexicon; a voice inputter; and a processor configured to: control the voice inputter to receive a user voice, obtain a word corresponding to the user voice using the user pronunciation lexicon, obtain a first pronunciation for a phoneme included in the user voice, compare the first pronunciation and a second pronunciation pre stored for the word, identify a pronunciation pattern by using a result of the comparing, and update the user pronunciation lexicon according to a pronunciation pattern rule obtained based on the pronunciation pattern, wherein the pronunciation pattern rule is a rule that a user repeats according to at least one of a pronunciation habit of the user and a pronunciation characteristic of the user.