It is argued that the emphatic reduplication of Jeiu Korean is a case of cooperation of universal grammar of perception and localized grammar of production. While the general shape of emphatic forms is made through maximizing the perceptual distance such as Maximize Distance of Formants, the specific arrangement of the perceptual principles is applied by phonotactic grammars which are realized as raising and fronting in vowels. This process of negotiation between two grammars is a motivation of the emphatic reduplication.