This minicourse was prepared for use with secondary physics students in the Dallas Independent School District and is one option in a physics program which provides for the selection of topics on the basis of student career needs and interests. This minicourse was aimed at providing students with a knowledge of the ways in which light, sound, and electricity are involved in everyday communication systems. The minicourse was designed for independent student use with close teacher supervision and was developed as an ESEA Title III project. A rationale, behavioral objectives, student activities, and resource packages are included. Student activities and resource packages involve defining communication, investigating communications-related vocations, building a string telephone and telegraph, studying wave theory, constructing a simple radio receiver circuit, and examining how a loud speaker works. (GS)