A method records verbal expressions of a person for use in a vehicle navigation system. The vehicle navigation system has a database including a map and text describing street names and points of interest of the map. The method includes the steps of obtaining from the database text of a word having at least one syllable, analyzing the syllable with a greedy algorithm to construct at least one text phrase comprising each syllable, such that the number of phrases is substantially minimized, converting the text phrase to at least one corresponding phonetic symbol phrase, displaying to the person the phonetic symbol phrase, the person verbally expressing each phrase of the phonetic symbol phrase, and recording the verbal expression of each phrase of the phonetic symbol phrase.