This document discusses audio visual aids and their use in education. It defines audio visual aids as instructional devices that convey messages through sound and visuals. It then classifies audio visual aids into three categories: audio aids, which convey messages through sound only; visual aids, which use images only; and audio visual aids, which combine both. The document outlines several advantages of audio visual aids, such as helping to clearly convey meanings, supplement spoken words, and attract audience attention. It also discusses factors to consider when selecting audio visual aids and some potential disadvantages, such as technical problems and distraction of students.