February, 2003, Earth Science Experiment:

Noise Pollution

- Purpose
- Background Information
- Equipment & Supplies
- Software & Probeware Set-up
- Experimental Procedure
- Data Analysis
- Conclusions and Extensions

PASPORT Sound Level Sensor
(PS-2109)

PASPORT Sound Level Sensor

ScienceWorkshop Sound Sensor
(CI-6506B)

ScienceWorkshop Sound Sensor

 Busy Street Scene
Purpose:

Students will use a Sound Level Sensor to measure the intensity of various sound sources. Measurements will be taken during different times of the day and at different locations and students will observe the changing levels.
 
Background Information:

Noise pollution can be defined as sounds or noises that are loud, annoying and harmful to the ear. Loud sounds can damage hearing, not only in humans, but also in animals. For example, noises in the ocean, such as the sounds of ships and other industrial activity, can interfere with a marine mammal's use of sound for navigating, hunting and communicating.

Ear DiagramSounds that are very loud and short in duration can damage a person's hearing quickly. Loud, continuous sounds can cause long-term effects on hearing. In general, sounds can be characterized by their frequency (or pitch) and intensity (or loudness). The vibrations that produce a sound are cyclical and are measured in hertz (Hz). One hertz (Hz) equals the number of cycles that occur per second. An adult with good hearing can generally hear frequencies in the range 20 to 15,000 Hz. Children can usually hear frequencies above 20,000 Hz.

The sound pressure level is measured in decibels (dB). For example, a whisper can occur in the range of 20-30 dB, while normal conversation is about 60 dB. A person that is shouting in your face could easily exceed 80 dB! PASCO's Sound Sensors can be used to measure the decibel levels of sound.

Hypothesize: Will the Sound Levels in a classroom increase or decrease during a class period? Why?

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Equipment & Supplies:

For each lab group:

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Software & Probeware Set-up:
  1. Ensure that your USB Link, Xplorer, or ScienceWorkshop 500 interface is connected to the computer.

  2. Click on one of the links below to download a pre-configured DataStudio file for this experiment, and then open the file.

    PASPORT users:  Windows (.zip file) or Macintosh (.sit file)

    ScienceWorkshop 500 users:  Windows (.zip file) or Macintosh (.sit file)

    When the file is opened, you should see a Graph Display of Sound Level vs. Time, as well as a Digits Display of Sound Level.

  3. Connect the Sound Level Sensor to the Xplorer or USB Link (PASPORT users) or plug the Sound Sensor into channel A of the 500 Interface (ScienceWorkshop 500 users).

    If you are using the ScienceWorkshop 500 Interface, be sure the interface is turned on and the Sound Sensor is associated correctly in the Experiment Setup window.

  4. Resize and arrange the display as needed.

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Experimental Procedure:

  1. Place the Sound Level Sensor in an open area in the classroom.

Data Collection & Recording:

  1. Click the Start button ( ) to begin collecting sound level data at the beginning of a class period.

  2. Allow the experiment to run until near the end of the class period.

  3. Click the Stop button ( ) to end the experiment.

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Data Analysis:
  1. Scale the axes to fit the data using the Scale to Fit button ( ) in the Graph toolbar.

  2. Use the Note Tool ( ) to annotate where on the graph any observed variables that contributed to large changes in Sound Level -- laughter, school bell, a textbook dropped onto the floor . . .

  3. Examine the graph and study the data. At what point was the sound level reading the highest? The lowest?

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Conclusions and Extensions:
  1. How did the sound level compare to your hypothesis or expectations?

  2. Explain why any difference occurred.

  3. How might a reading from one class period to another differ? Why?

  4. As a comparison, if you’re using an Xplorer datalogger or ScienceWorkshop 500 interface, take the Sound Level Sensor outdoors and obtain a measurement of street traffic or in the school parking lot, in the cafeteria during lunch, a basketball game in the school gymnasium, etc. Is it higher or lower than your classroom reading? Why?

  5. Discuss situations in which hearing loss is possible and ask your students to create a list of suggestions on how to prevent hearing loss. Discuss the use of technological solutions such as earplugs and sound-absorbing or reflective materials in building construction.

  6. Discuss other sound-related issues, such as how human-generated noise can disturb an environmental habitat. This will hopefully encourage some interest in how individuals working in scientific and technological fields are becoming increasingly sensitive to this issue. Ask your students for examples.


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