Propagation of Sound

The purpose of McGough and Houghton's investigation was to compare the difference between the propagation of sound through two different cars, a common car and a luxury car.

McGough and Houghton set up our investigation by using a tone generator attached to a speaker in the trunk of each car. They then used different variables and recorded the magnitude of the sound in decibels outside of the car from a distance of three feet. The variables investigated were amplitude (high and low), windows (up and down), engines (on and off) and three different frequencies (.25, .5, and .75 K Htz). We used these variables to set up a DOE.

Their results showed that the Sunbird had a 9.4% increase for .25 K Htz frequencies. 1.5% increase for .5 K Htz frequency,and 9.8% increase for .75 K Htz frequencies over the Mark VIII.

McGough and Houghton have concluded that the Mark VIII propagates less sound than the Sunbird, because the recorded values were lower on the average. They also found that the lower frequencies were louder outside the cars. They think this happened because the lower frequencies vibrated the cars more than the higher frequencies.

Research Done By:

Matt Houghton
Center Line

Tom McGough
Center Line