Image

Image caption

Fig. 1. Dolphins use sound to navigate in their everyday life.

Image copyright and source

Image courtesy of Axelle B

Phenomenon:

Animals send and receive sounds to communicate and explore their environment (Fig.1).

Inquiry:

How is sound used to communicate information?

Guiding Questions:

1. How do animals receive information with their senses?
2. How do animals process information?
3. How do animals respond to information?
4. How do dolphins used sound to get and share information?

Activity:

In this activity, you will explore how dolphins use sound and echolocation to find an object!

Materials:

• Student worksheet and teacher guide (attached below):
  
  ACTIVITY SHEET

  Student Worksheet: Echolocating with Dolphins (Movement Game)

  TEACHER GUIDE

  Teacher Guide: Echolocating with Dolphins (Movement Game)

• Optional: Separate target fish download
  
  ACTIVITY SHEET

  Extra Student Worksheet: Target Fish
• Blindfold
• Measuring tool (such as ruler, tape measure, or yard stick)
• Timer
• Optional: Internet access
  Note: this activity directs you to use the NOAA Fisheries, Sounds in the Ocean website to play examples of dolphin sounds.
• Optional: Speaker to play sounds

Procedure:

1. Follow along on your worksheet for instructions to model dolphin echolocation.
2. Animals have senses (such as the use of sound, sight, smell, taste, and touch) that have adapted to the environment where they live. Discuss and answer with your classmates:
   
   1. How do you use your senses in your daily life?
   2. How do animals use these senses differently than humans? (Hint: think about observations
      you've made of your own pets).
3. Read the background information below:
   

   Background Reading Animals receive information through their senses, process information in their brain, and then respond. The better an animal can sense and respond to its environment, the more likely it is to survive and reproduce.     Image Image caption Fig. 2. A dolphin sends out a sound and interprets the echo to know if the object is a prey item. Image copyright and source Image courtesy of Wikimedia Commons The use of sound is a powerful sense underwater. Sound actually travels faster in water than it does in air! Toothed whales, like dolphins, use echolocation to receive sound information about their environment. To use echolocation, a dolphin sends out a series of clicks. The sound vibrations then bounce off of an object and return, or echo, back to the dolphin (Fig. 2). These echoes are processed in the dolphins brain to create an 'image' that gives information about the distance, shape, and characteristics of the object. This allows dolphins to 'see' further than their eyes are able. Dolphins rely on echolocation to find prey, but they also produce and use other sounds to communicate with one another. Dolphins can make a range of sounds that differ in frequency and pitch. The sounds dolphins use to communicate are generally lower pitched whistles. Individual dolphins have their own signature whistle that is specific to them—sort of like a name!

4. Optional: Go to the NOAA Fisheries Sounds in the Ocean page and listen to sample dolphin (or other toothed whale) sounds. Discuss what you hear with your classmates.
5. In teams of two, choose one person to be the 'dolphin' and the other to be the 'echo.' 
   Note: You will switch roles and each student will get to be both the dolphin and the echo.
   
   1. ​The role of the dolphin will be to locate, while blindfolded, the center of the target (and therefore capture the fish) using echolocation. 
   2. The role of the echo will be to respond to the sounds of the dolphin to help guide them to capture the fish.
6. Come up with your own signature sound or whistle that is unique to you as the dolphin. Write it out: _________________________________________
7. As a pair, come up with the different echo sounds that signal directions (left, right, forward, backward, and on target) to help find your target fish. Fill in the table below to help you remember. 
   

   ---

   Some helpful tips:
   • You will have to remember what direction your sounds represent. Choosing sounds that are similar to the direction will make it easier. For example, left could be "lah" and right could be "rah."
   • Each sound indicates one step. For example, one "lah" from the echo tells the dolphin to move one step to the left.

Safety note: make sure that your environment is safe and clear of tripping hazards. As the echo you are also acting as the lookout person to help ensure dolphin is safe!

8. Practice making and listening to your sounds.
9. Choose an area with a large open space where it will be safe to explore while blindfolded. This will represent your ocean area!
10. Your role as the echo:
    
    1. When the dolphin is blindfolded, place their target fish on the floor somewhere in your 'ocean area'.
       Note: For a harder challenge, fold or cut the paper to reveal only the target fish.
    2. Let the dolphin know you are ready and listen for their call.
    3. When they make their call, respond with the appropriate echo (refer to your table) that directs them closer to the target fish.
    4. Continue for up to one minute or until they reach the target.
    5. When the dolphin reaches the target (or after one minute), indicate that they should stop where they are and remove the blindfold.
    6. Repeat the whole process for at least three trials. Be sure to move the target before the next trial!
11. Your role as the dolphin:
    
    1. Read the instructions b-g before you put on the blindfold.
    2. Make your signature sound and wait for the echo's response.
    3. Move in the direction indicated by the echo's call.
    4. Repeat for up to one minute (or until you reach the target).
    5. When the echo indicates that you have reached the target (or after one minute), stop where you are and remove your blindfold.
    6. Use the measuring tool to measure how close you were to the target fish and record the
       distance and your observations in your table below.
    7. Repeat these steps for 3 trials.
    8. Now that you know what to do, put on your blindfold and follow steps b-f above. No
       peeking!
12. Switch roles and repeat!

Image

Image caption

Fig. 3. Use this target to test your echolocation skills! (Note: you can also find this image in the attached worksheet)

Image copyright and source

Image by Emily Sesno

Activity Questions:

1. What went well for you:
   1. as the echo (giving information)?
   2. as the dolphin (receiving information)?
2. What were some challenges you faced:
   
   1. as the echo (giving information)
   2. as the dolphin (receiving information)
3. In order to locate the target when you were the dolphin:
   
   1. What senses did you use to receive information?
   2. How did you process the information you received from the echo?
   3. How did you respond to the information from the echo?
4. How is this activity similar to the ways that dolphins use echolocation in real life?
5. How might dolphins use sound in other ways?
6. How do you think that communication between dolphins is different than between humans?
7. What are some challenges that scientists face when studying dolphin echolocation and communication?