Introduction

In this activity, we will learn about sound and use the LEGO sound sensors to control a crane.  Sound travels in all directions from a source--it can be thought of as a growing sphere moving away from the source.  The intensity of a sound is dependent on the power produced by the source and the size of the sphere at a certain distance away.
 
 
 
 
As you can tell, the intensity level changes a lot with distance and can vary over a huge sweep of values.  We use the decibel scale so that the entire range of human hearing can be placed on a chart between 0 and 100.  Any louder than 100 dB, and a sound can cause damage to your hearing.  The equation for decibels is the following:
 
Here are some examples with decibel and intensity levels:
 
 

Materials

LabVIEW for LEGO MINDSTORMS
LEGO MINDSTORMS NXT kit

Teaching Standards

In this lab students have the opportunity to understand the following: 
1. How to create a system that controls movement to accomplish a goal
2. Event Structures/Flags
3. Parallel Processing
4. Principles of Sound--intensity, decibels
5. Sound sensors
6. Computer programming
7. Electronics and motors
8. Teamwork and collaboration

We recommend linking your project's content to the nationally recognized Common Core Standards for literacy in science and math.