A method, a system, and an apparatus for identifying and correcting sources of problems in synthesized speech which is generated using a concatenative text-to-speech (CTTS) technique. The method can include the step of displaying a waveform corresponding to synthesized speech generated from concatenated phonetic units. The synthesized speech can be generated from text input received from a user. The method further can include the step of displaying parameters corresponding to at least one of the phonetic units. The method can include the step of displaying the original recordings containing selected phonetic units. An editing input can be received from the user and the parameters can be adjusted in accordance with the editing input.