1. The problem statement, all variables and given/known data A public-address system is usually used in the school assembly to obtain better attention from students. Carry out a study on the factors affecting the audibility of sound. 2. Relevant equations 3. The attempt at a solution Objective: To study how does the frequency of the sound are affected by tension, length and material of the string. This objective was rejected by teacher. I had come up another objective which is to investigate the relationship between the amplitude and frequency and the loudness of sound was also rejected. Any other suggestions regarding this topic?