1. A prosody editing apparatus comprising: a storage configured to store attribute information items of phrases and one or more first prosodic patterns corresponding to each of the attribute information items of the phrases, the attribute information items each indicating an attribute associated with a phrase, the first prosodic patterns each including parameters which indicate a prosody type of the phrase and expresses prosody of the phrase, the parameters each including elements not less than the number of phonemes of the phrase; a first selection unit configured to select a phrase including phonemes from text to obtain a selected phrase; a search unit configured to search the storage for one or more second prosodic patterns corresponding to an attribute information item that matches an attribute information item of the selected phrase to obtain as a prosodic pattern set, the second prosodic patterns being included in the first prosodic patterns; a normalization unit configured to normalize the second prosodic patterns respectively; a mapping unit configured to map each of the normalized second prosodic patterns on a low-dimensional space represented by one or more coordinates smaller than the number of the elements to generate mapping coordinates; a display configured to display the mapping coordinates; a second selection unit configured to obtain coordinates selected from the mapping coordinates as selected coordinates; a restoring unit configured to restore a prosodic pattern according to the selected coordinates to obtain a restored prosodic pattern; and a replacing unit configured to replace prosody of synthetic speech generated based on the selected phrase by the restored prosodic pattern.