Speech sounds are air pressure vibrations produced by air exhaled from the lungs and modulated and shaped by the vibrations of the glottal cords and the vocal tract as it is pushed out through the lips and nose. Speech signals, in addition to communicating the linguistic information, convey a multitude of other information including gender, age, accent, intent, emotion, humor and the state of health of the speaker. There are several neurological (e.g., aphasia, dysarthria, and apraxia) or anatomical (e.g., cleft lip and palate) factors that could affect the intelligibility and audibility of the human speech. In this paper we present our work in developing a training system based on the resonant frequencies (widely known as formants) of the vocal tract to help a human subject with speech impairment train himself or herself to improve the intelligibility and audibility of his or her speech.