Speech acquisition focuses on the development of spoken language by a child. Speech consists of an organized set of sounds or phonemes that are used to convey meaning while language is an arbitrary association of symbols used according to prescribed rules to convey meaning.While grammatical and syntactic learning can be seen as a part of language acquisition, speech acquisition focuses on the development of speech perception and speech production over the first years of a child's lifetime. There are several models to explain the norms of speech sound or phoneme acquisition in children.