Speech disorder refers to the situation that affects the ability of a person to produce sounds that generates words. People of any age can be affected by speech disorders. Speech disorders symptoms varies broadly contingent on the cause and the disorder severity. Multiple speech disorders can be developed in the people with different symptoms. Approximately one-fifth of theworld’s population suffer or have suffered from voice and speech production disorders due to diseases or some other dysfunction. Thus, there is a clear need for objective ways to evaluate the quality of voice and speech as well as its link to vocal fold activity, to evaluate the complex interaction between the larynx and voluntary movements of the articulators (i.e., lips, teeth, tongue, velum, jaw, etc.), or to evaluate disfluencies at the language level. With advances in speech signal processing and natural language processing, there has been recent interest in developing tools to detect more subtle changes in cognitive-linguistic function. This paper discusses on various speech disorders in children and adults such as apraxia, stuttering, voice disorders involving the larynx, Aphasia and dysarthria. This paper also presents a survey on different methods used for processing speech disorders.