2. Properties of Sound: Page 40 QUESTION: How do singers change the pitch of their voice? OBJECTIVE: Students will be able to define and describe the common properties of all sound. VOCABULARY:loudnesspitchDoppler Effect

3. Properties of Sound Write these questions onto page 40 SKIP A LINE BETWEEN EACH QUESTION 1.What properties are common to all sound? 2.What causes some sounds to be loud? 3.Why does a tuba sound different than a flute? 4.What units are used to measure loudness? 5.How does a singer change the pitch of their voice? 6.What is a common example of the Doppler Effect?

4. What are the properties of sound? The properties of sound are loudness, pitch and the Doppler Effect.

5. Loudness Two factors cause some sounds to be loud. The greater the energy used to make the sound, the louder the sound. The closer you are to the sound, the louder the sound.

6. What’s Loud? What one person thinks is loud, another person might not. Scientists measure the loudness of a sound in a unit called decibels. The machine used to measure the loudness is called a decibel meter.loudness of a sound in a unit called decibels

7. Pitch and Frequency Another property of sound is pitch. Pitch is how “high” or how “low” something sounds.pitchPitch Most people would say that a tuba has a low pitch. Most people would also say that a piccolo has a high pitch. Pitch depends on frequency. The higher the frequency, the higher the pitch.

8. Range of Human Hearing Human being, even those people with above average hearing cannot hear all sound vibrations. There is a lower limit and upper limit to what people can hear. lower limit and upper limit to what people can hear. Try this hearing test.

9. Changing Pitch Pitch is changed by loosening and tightening the object making the vibration. Watch the demonstration with the balloon. A singer uses the muscles in their throat to loosen and tighten their vocal chords.

10. The Doppler Effect This change in pitch is called the Doppler Effect.change in pitch Doppler Effect Have you ever noticed how the sound of a helicopter or motorcycle or an ambulance changes when it is coming towards you and then passes you?

11. Properties of Sound: Review page 40 Check that the answers to these questions are in your notes. 1.What properties are common to all sound? 2.What causes some sounds to be loud? 3.Why does a tuba sound different than a flute? 4.What units are used to measure loudness? 5.How does a singer change the pitch of their voice? 6.What is a common example of the Doppler Effect?

12. VOCABULARY Loudness- perception of the energy of a sound. Pitch- perception of the frequency of a sound. Doppler Effect- the change in frequency of a wave as its source moves in relation to the observer.