1. A system for supporting text-to-speech, comprising: a learning data generating unit which recognizes inputted speech, and generates first learning data in which wordings of phrases are associated with readings thereof; a frequency data generating unit which generates, on the basis of the first learning data, frequency data indicating appearance frequencies of both wordings and readings of phrases; a language processing unit; and a setting unit which sets frequency data in the language processing unit for generating, from a wording of text, a reading corresponding to the wording, on the basis of appearance frequencies of readings corresponding to the wording in order to approximate outputted speech of text-to-speech to the inputted speech.