Developed by the Oregon Elementary English Project, this curriculum unit intended for grades three and four aims to (1) help students become aware of some of the sounds of the language; (2) help students discover how some of these sounds are pronounced; and (3) help students understand that with a limited number of sounds they can produce an unlimited number of words. Lesson 1 introduces students to the study of sounds by having them isolate some of the various sounds of English. Lesson 2 explains how the positions of teeth, lips, and tongue affect some of the sounds. Lesson 3 reinforces the concept that combined sounds produce words, and, finally, lesson 4 helps students discover both those sounds produced by forcing air through the nasal cavity and those produced by forcing it through a very narrow opening in the mouth. Each lesson is accompanied by a statement of its purpose, suggested procedures and materials, possible extensions, and student exercises. A packet of supplementary materials to be used in conjunction with some of the lessons is also provided. (See related documents CS 200 482-487, and CS 200 489-499.) (HS)