1. Higher Intensity (Volume)
II. Characteristics of Sound (continued)
D. Sound has different levels of “Intensity”
1. Intensity = Volume
2. Intensity is determined by the Amplitude
More Compressed Wave
Greater Amplitude
Greater Energy
Higher Intensity (Volume)

2. Greater Compression (Amplitude)
Greater Intensity
Louder Volume
Less Compression (Amplitude)
Lower Intensity
Softer Volume

3. 3. Intensity is measured in units called decibels (dB)
a. More decibels = louder volume
b. Each increase of 10 decibels has 10-times more intensity than the one before it.
● ex: 10 dB increase = 10X more intensity
20 dB increase = 100X more intensity

4. NO SOUND (HUMAN THRESHOLD)
• Total silence

5. E. Pitch is how high or low a wave sounds.
1. Frequency determines pitch
2. Measured in Hertz (Hz)
3. Oscilloscopes analyze sound waves
Convert compressional sound waves into transverse waves.
b. Measure frequency and amplitude

6. Low Amplitude (quiet)
High Amplitude (loud)
Low Frequency (low pitch)
High Frequency (high pitch)

7. 4. Human voice pitch decreases with age
a. Vocal chords get longer, thicker, and
less flexible so they vibrate slower
5. Different animals hear different ranges of pitch
a. Ex. Human hearing is different than dogs

8. Frequency (Hz) of Animal Hearing
HUMAN
DOG
DOLPHIN
BAT
CAT
FROG
FISH 20
100
10,000
50,000
200,000 10 50
1000
20,000
100,000
infrasonic
Frequency (Hz) of Animal Hearing
audible (to humans)
ultrasonic