Echoes and Echolocation

Objectives:

• Students will be able to define the term echo.

• Students will be able to describe how echoes are created.

• Students will be able to describe how scientists use echoes to detect the location of objects.

• Students will be able to describe how animals use echoes to locate objects they cannot see.

• Students will be able to describe the Doppler Effect and its relationship to the pitch of sounds.

Suggested Grades:

5th Grade - 6th Grade - 7th Grade

Lesson Procedure:

Print the reading comprehension worksheet passage and questions (see below).

Students should read the passage silently, then answer the questions. Teachers may also use the text as part of a classroom lesson plan.

Lesson Excerpt:

Sound waves can travel in all directions. They can even bounce off of surfaces and travel back in the direction they came from. When this happens, an echo is created. Echoes are reflected sound waves. If you call out a sound and the sound is reflected back, you will be able to hear it again after you have already said it! If the sound reflects back from more than one surface, you may hear the same sound several times.

Sometimes sound is reflected from a surface very near to where the sound is created. In that case, the echo will not necessarily create the sound more than once, but the sound will be a lot richer than it would be in another environment. For example, if you sing in the shower, you may notice that your singing voice sounds especially good. This is because echoes are bouncing back and forth off the shower walls, making it sound almost as if there were background singers in the room with you!

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