Intensity of Sound Waves
Lorena Zoltan
Sir Winston Churchill Secondary
Floor Location : M 079 D

It's important to take note of the varying effectiveness of materials in blocking sound. Various types of materials are widely used solutions for the purpose of blocking sound. The use of inappropriate materials in certain situations, such as construction worker sound-blocking headphones, could lead to a loss of hearing. Based off of this problem, the question I have considered in this project is:

How does the loss of intensity (measured in decibels) of sound waves change when passing through materials of different densities?

I hypothesized that the material with the greatest density will have the most intensity lost; this material being metal.This experiment tested which materials are best at blocking out sound by using five different materials of varying densities and same volume, as the independent variable. First, I measured the intensity of a controlled sound source. Then the intensity of the same sound source that was passed through each material was measured. Lastly, after the sound source was passed through each material, their intensity was subtracted from the original sound sources’ intensity and turned into a percentage of intensity lost. After comparing the amount of sound that goes through each material, metal had the highest intensity loss by over four decibels and wool had the least intensity loss. Clay had the second most intensity loss followed by wood then foam. Although metal is the most expensive material to buy, it is by far the most effective at blocking out sound. Headphones are difficult to be completely made out of clay however there are possibilities of making headphones with metal. This experiment benefits people in instances where they need to block noise from around them such as not wanting to hear their neighbours from the other side of the wall. In conclusion, metal was the best sound insulator therefore my hypothesis was correct.