Noise Pollution

Let’s look at the topic of noise pollution, including: What is it? Who does it affect? What causes it? How do we measure it? How can we control it?

What is noise pollution? Noise is unwanted sound. Noise pollution is the excessive noise that may harm the activity or balance of human or animal life.

Who does noise pollution affect? Everyone! Sound is an important part of everyday life: for communication, for enjoyment or for alerting us to danger. But in some situations a sound can distract us, break our concentration or, if it’s very loud, even harm us. When this happens, the sound becomes unwanted noise, and it can negatively affect both our physical and mental health.

Extra noise in the environment affects more than the human population. When we introduce artificial sounds to an animal’s habitat, problems are created. It can affect an animal’s ability to hear or make it difficult for it to find food, locate mates and avoid predators. It can also impair its ability to navigate, communicate, reproduce and participate in normal behaviors. Two examples: Wild birds are 20% more likely to choose a quiet place to nest. Noisy areas deter birds that are vital to seed dispersal and tree growth. Wild frogs’ croaks can be dampened by up to 98% in urban environments. Increased noise pollution could lead to less reproduction and declining populations of some frogs.

What can cause noise pollution? The source of most outdoor noise worldwide is mainly caused by: machines transportation systems motor vehicles aircraft trains

Examples of machine-related noise pollution:

Examples of transportation system-related noise pollution:

Examples of aircraft-related noise pollution:

Examples of motor vehicle-caused noise pollution:

Examples of train-caused noise pollution:

How do we measure sound? The sound pressure level is measured in decibels (dB). A whisper is approximately 30 dB, normal conversation about 60 dB, a lawnmower around 90 dB and an ambulance about 130 dB.

How can we control noise pollution? Baffles Any object designed to muffle or greatly reduce airborne sound. Some baffles are built into ceilings. Baffles frequently hang and are made of materials designed to absorb sound waves. The sound tube in Melbourne, Australia, is designed to reduce roadway noise in an attractive way.

How can we control noise pollution? Sound Barriers Any object designed to block or reflect airborne sound.

It makes sense that the denser the material, the more sound it can stop.

In addition, some materials can reflect sound waves and some can absorb sound waves.

Why is this important to you?

The metro train is coming to Loudoun County! The Silver Line is a 23-mile extension of the Metrorail system with new tracks extending from East Falls Church, through Tysons and Reston, and eventually to Washington Dulles International Airport and further west to Ashburn.

This will be a convenient way to travel, but the increased noise will affect the local environment. Today, you get to do something about that. Silver Line Sound Barrier Challenge Your challenge is to design a sound barrier as a model of the ability to reduce the amount of sound pollution that the metro train will cause.

Design guidelines: You can only use the materials given to you. Your barrier can be no longer than 22 ½” long and 8 ¼” high and 2” wide. Your barrier must be free-standing. Your barrier must reduce the decibels caused by a model train on a track.

Project steps: Practice reading decibel levels around the school. Record the decibel level of a model train on a track without a barrier 3 times and find the mean, median, mode, and range. Build your barrier. Record the decibel level of a model train on a track with your barrier in front of the track 3 times and find the mean, median, mode and range. Redesign your barrier to make it more effective. Repeat step #4. Graph your results.