Abstract:Speech is an expression of thoughts which is performed by interacting with people. As every technique in this world it has its own drawbacks, which includes inability to understand the sound or perceive it either from listener end or disruptive atypical speech generation at the speaker end. In life we encounter number of people who are mentally unstable. In addition to the issues faced in performing basic work like confident walking public behavior and presentation, they may also suffer heavily with the speech stigma. While they speak they often sound like noise and are not understandable. Mental retardation is a relative term. Its meaning depends on the requisites of a society. A society of well grown and groomed people demands presence of intelligence and intellectualism, they search for person's social behavior to decide if a person is mentally impaired or not. This study is an attempt to find the differences and observe the pattern of pitch variation in 2 main categories of Mental retardation i.e. Mild mental retardation and moderate mental retardation.