Investigation 2: Good Vibrations Part 1 Vibration and Pitch Physics of Sound Investigation 2: Good Vibrations Part 1 Vibration and Pitch

Objectives I can identify HIGH and LOW pitches. I can compare the vibrations of high and low pitches. I can compare pitch and volume. I can explain what happens to vibrations when the pitch changes.

Voice the Vibrations Remember the observations you made with the tone generator, the long gong, and the tuning forks. Do you remember these vocabulary words? Sound source Sound receiver Vibration Volume What is the source of the sound of my voice? Does a person’s voice make vibrations? Put your fingers on your throat and feel the vibration as you hum.

Give Your Pitch PITCH describes how high or low a sound is. High-pitched sounds include squeaks and screeches. Low-pitched sounds include rumbles and growls.

Generate some body language Stand next to your desks. Squat low when you hear a low pitch. Begin standing when you hear a mid-range pitch. Stand tall when you hear a high pitch. Reach up as high as you can when the pitch is very high.

Make sounds with a tongue depressor Watch how to do it: Put the tongue depressor on your desk so that the end sticks out over the edge like a little diving board Use the ‘heel’ of your hand to hold the Tongue depressor Pluck the tip of the tongue depressor Your job: Discover ways to make high and low pitches with a tongue depressor

Share results Return materials How did you make high- and low-pitched sounds? What is the highest pitch you could make? What is the lowest pitch you could make? Where are the vibrations? Compare the vibrations of the low and high pitches. Are the vibrations different? How?

Fiddle around Web Link What pitch do you hear from the long string? What do you see? What pitch do you hear from the short string? Do the two strings vibrate the same?

Frequency Faster vibrations make higher pitches. Slower vibrations make lower pitches. How fast or how slow something is vibrating is called the frequency of the vibration.

Compare pitch and volume Watch the beans on the tone generator. What do you think you will see as the pitch changes? What happens to the beans as the pitch changes? What is pitch? What happens to the vibrations when the pitch changes?

Compare pitch and volume Find the “bounciest” pitch level. Observe the beans as the volume changes. What is volume? What happens to the vibrations as the volume changes?

The voice Feel your throat as you make high and low pitched sounds. Keep the volume at a whisper. What do you feel? Now, keep the pitch the same as you increase the volume from a whisper to a hum. What happens to the vibrations?

Vocabulary review PITCH FREQUENCY Describes how high or low a sound is How fast or slow something is vibrating

Objectives I can identify HIGH and LOW pitches. I can compare the vibrations of high and low pitches. I can compare pitch and volume. I can explain what happens to vibrations when the pitch changes. EXIT SLIP