Repeat After Me is an application that allows for the recording of one's own voice along side the TTS technology built into OS X. The software graphs both your voice and the TTS(Text-to-speech) voice and allows for imposing the pitch of your voice to that of the computer TTS voice, thus allowing an attempt of a more humanized infliction upon the TTS audio.
Tests the operating system's phonemic translation engine, creates graphs of the generated tone, to visually adjust the intonation, and records samples for reference.
You can read about it more from its Documentation.
from the Documentation..