11. A machine readable non-transitory storage medium for use in a computer, the medium containing program instructions executable by the computer to perform a speech synthesis information editing process comprising: providing phoneme information that designates a duration of each phoneme of speech to be synthesized; providing feature information that designates a time variation in a feature of the speech; providing a phoneme expansion/compression rate that is set for each phoneme; and changing a duration of each phoneme designated by the phoneme information in accordance with an expansion/compression degree that is provided for each phoneme, wherein the expansion/compression degree is obtained according to the feature designated by the feature information for the phoneme and the phoneme expansion/compression rate that corresponds to the phoneme; and outputting for display a phoneme indicator having a length set according to the duration of each phoneme designated by the phoneme information, and updating the displayed length of the phoneme indicator based on the duration of each phoneme changed by the edition processing unit.
11. A machine readable non-transitory storage medium for use in a computer, the medium containing program instructions executable by the computer to perform a speech synthesis information editing process comprising: providing phoneme information that designates a duration of each phoneme of speech to be synthesized; providing feature information that designates a time variation in a feature of the speech; providing a phoneme expansion/compression rate that is set for each phoneme; and changing a duration of each phoneme designated by the phoneme information in accordance with an expansion/compression degree that is provided for each phoneme, wherein the expansion/compression degree is obtained according to the feature designated by the feature information for the phoneme and the phoneme expansion/compression rate that corresponds to the phoneme; and outputting for display a phoneme indicator having a length set according to the duration of each phoneme designated by the phoneme information, and updating the displayed length of the phoneme indicator based on the duration of each phoneme changed by the edition processing unit. 16. The machine readable non-transitory storage medium according to claim 11 , wherein: an expansion/compression coefficient is obtained according to a duration, the expansion/compression rate and a pitch, and the expansion/compression degree is a ratio of the expansion/compression coefficient to a sum of expansion/compression coefficients of phonemes involved in a target interval.