Fuel combustion does not only produce gaseous pollutants. It also produces acoustic pollutants. The explosive reaction of fuel with oxygen creates loud sounds that can potentially damage hearing. The intensity of these sounds is reduced by the muffler. The muffler serves as some sort of sound deadener that eliminates the noise of the exiting exhaust gases. The quality of sound is also improved in the process. Hence, some automobile owners install performance mufflers simply to improve the sound of the exhaust. This is common in hot rod cars and other modified cars intended for racing or off-road driving. Some mufflers are even conspicuously displayed.
In most automobiles, the mufflers are found at the rear portion. In some fancy cars, the mufflers are found elsewhere. Sometimes they may be found on the sides or on top of the engine compartment itself. Regardless of the configuration or location, the muffler serves the same purpose and it is fundamentally standard in design. Simple as it may seem, the muffler is actually a precision component. It is precisely tuned as a wind instrument. However, instead of producing sounds, it eliminates sounds. The muffler has special chambers and holes. It is through these chambers and holes that the sounds are eliminated.
Sounds are eliminated by the muffler through the process known as destructive interference. When the exhaust sounds pass through the muffler, echoes are created. These echoes are identical to the original sounds but they have reversed amplitude crest. When the original sound waves and echo waves meet, they mutually cancel each other. In this manner, noise is eliminated. Nonetheless, exhaust sounds are far too complicated to be totally cancelled. The intensity and quality of the sounds are merely modified to be less destructive or disorganized. The sounds that exit the mufflers are less intense and more pleasing to the ears.
