Which Household Materials Absorb The Maximum Sound (basic felt, foam sheet, plastic sheet, birch plywood, heavy duty aluminum foil, poster board paper)?
Pravnoor Mundra
St John's School
Floor Location : J 174 D

In this experiment, different household materials (basic felt, foam sheet, plastic sheet, birch plywood, heavy duty aluminum foil, poster board paper) were tested to see which materials absorb the maximum sound. Same size wooden frames were made using oak wood stripes. The materials were glued to wooden frames and were tested by placing a bluetooth speaker inside. A decibel meter was placed outside the frames and was used to measure the outgoing sound. A reference frame was used with no material on it. It was hypothesised that aluminum foil would absorb the most sound due to its strong molecular structure. Despite aluminum foil having a strong molecular structure, the aluminum foil emitted the most outgoing sound possibly due to its flexible structure.The vibrations in the aluminium were very loud and were audible during the test. However, the plastic sheet emitted the least outgoing sound probably due to a sandpaper like effect and its rough surface. This sandpaper like effect could have caused vibrations, which in turn could have caused tiny amount of heat to generate. When the heat was generated, then the sound energy could have gotten transferred into heat energy, hence absorbing the maximum sound when compared to other household materials tested. Further studies could be conducted to show the relationship between how different thickness and types of materials could have an affect on the outgoing sound being emitted. Future studies can also be conducted to study the effect of heat or temperature on the speed of sound waves.