Activity 2

Activity Title: 

Understanding Sound Measurement

Unit Title: 

Feel The Noise

Estimated Duration: 

2 Days

Setting: 

Classroom

Materials:

Worksheets, graphing calculators (optional), sound meter or sound meter app, app such as Dog Whistle (free), Tone Generator app (free), or a method of generating sound of a given frequency. 

Worksheet: Measuring  Decibels

Worksheet: Sound Pollution 

Teacher Advance Preparation:

The teacher should familiarize themselves with the concepts of sound and the measurement of sound in watts/ square meter converted to the decibel scale.  

Author: 

David Macmorine

Date: 

July 2014

Activity Objectives

The students will be to identify the nature of sound measurement

Capture 2

Here is an example of a decibel meter.  Peak is the highest sound monitored regardless of length of time. Max highest decibel reading over a given time period (depending on the specific meter).  Average is the average over the time period the decibel meter has been monitoring sound. 


Guiding Questions
  1. Now that we have studied a way to measure sound, are there any other factors involved in sound?
  2. What is a speaker, that is, a stereo speaker that produces sound?
  3. What does the word ‘stereo’ mean?
  4. Think about a stereo speaker or your ‘earbuds’ for your phone or mp3 player.  How does it produce sound?
  5. Some PA speakers are a collection of large speakers and small speakers.  Why do they have different sizes?
  6. What is frequency? 
  7. Can a high frequency sound and low frequency sound produce the same decibel level?
Academic Standards

HS-PS4-1. Use mathematical representations to support a claim regarding relationships among the frequency, wavelength, and speed of waves traveling in various media.

HS-PS4-5. Communicate technical information about how some technological devices use the principles of wave behavior and wave interactions with matter to transmit and capture information and energy.* 

Activity Procedures
  1. Ask the students about the sounds all around us.
  2. Have examples of stereo speakers, headphones, amplifiers, or point out any public address speakers in your classroom.
  3. Ask the students if they know how the speakers produce sound. 
  4. Some people have ‘high’ voices some have ‘low’ voices.  Ask the students if they know why.
  5. Introduce the sound measurement device of your choice and how it is used.
Differentiation

Students may have not given sound measurement much thought.  Sound measurement in decibels is taken over time so when students read a decibel meter and see Peak giving a higher number than Max emphasize the difference being the Peak is the loudest instantaneous sound whereas Max is the loudest sound over a period of time.