Adjustment of the pause length for text-to-speech synthesis

An apparatus for converting text data into speech signal, comprises: a phoneme determiner (28) for determining phoneme data corresponding to a plurality of phonemes and pause data corresponding to a plurality of pauses to be inserted among a series of phonemes in the text data to be converted into sound signal; a phoneme length adjuster (24) for modifying the phoneme data and the pause data by determining lengths of the phonemes, respectively in accordance with a speed of the speech signal and selectively reducing the length of at least one of the pause in the text data to a pause length which is less than the pause length corresponding to the speed of the speech signal; and an output unit for outputting speech signal on the basis of the adjusted phoneme data and pause data by the phoneme length adjuster (24).