A speech synthesis system for storing in advance a degree of modification
of prosodic data in a prosodic data modifying rule apparatus, the degree
of modification corresponding to an approximate cost and being stored as a
modifying rule, a prosodic data retrieving section for retrieving a
prosodic data stored corresponding to a key data for use in retrieval, the
prosodic data retrieved according to a degree of matching between the
input data and the key data, the degree of matching represented by the
approximate cost, a modifying section for modifying the retrieved prosodic
data based on the degree of matching and the modifying rule stored in the
prosodic data modifying rule means, and an output section for outputting
synthesized speech based on the input data and the modified prosodic data.
