1. A method of operating a voice user interface, the method comprising: customizing, for a user, one or more audio prompts presented to the user via the voice user interface based at least in part on at least one spoken utterance of the user, wherein customizing the one or more audio prompts based at least in part on the analysis comprises: recognizing a personality trait associated with the user through analysis of the at least one spoken utterance of the user, wherein recognizing the personality trait comprises: receiving at least one morphological attribute of a plurality of words spoken by the user in the at least one spoken utterance, the at least one morphological attribute comprising a number of compound words that are in the plurality of words; and determining the personality trait associated with the user based at least in part on the at least one morphological attribute of the plurality of words spoken by the user, wherein the determining comprises determining whether the number of compound words exceeds a threshold; and selecting, based at least in part on the personality trait, between presenting a first audio prompt or a second audio prompt via the voice user interface; and outputting the one or more audio prompts, customized for the user, for presentation to the user via the voice user interface.