This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on operating sound-measuring equipment. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) selecting decibel ranges, checking the conditions of batteries, and measuring sound levels; (2) testing decibel level response and using a sound level calibrator; and (3) screening survey measurements. Each lesson contains objectives, recommended methods and locations for practice, performance criteria, equipment and supplies to perform a task, detailed step-by-step instructions for learning a task, and performance exercises. Two performance tests cover calibrating exercises the general-purpose sound level meter and making screening survey measurements. (CT)