1. Chapter 12-1: Sound Waves

2. Car Audio
Power of Sound Power of Sound 2 How to do your hair without a comb

5. Characteristics of Sound Waves
Frequency is the number of cycles per unit of time.
Although sound waves can stretch through any frequency, humans can only detect frequencies between 20 Hz and Hz.
20 Hz would be a deep bass sound, where Hz is very high pitched.
Sound waves less than 20 Hz are called infrasonic waves
Sound waves greater than Hz are called ultrasonic waves

6. Did you know…
Elephants use infrasonic sound waves to communicate? This allows them to communicate over great distances. In perfect conditions (low wind, low heat) elephant communication can travel up to 10km.
2. Bats use ultrasonic waves to communicate and to sense where they are. Bats are capable of producing up to 200 pulses per second at very high frequencies (up to 110,000 Hz)

7. Human Echolocation – Daniel Kish
Wikipedia: Daniel Kish is an American expert in human echolocation and the President of World Access for the Blind (WAFTB), a California-registered nonprofit organization founded by Kish in 2000 to facilitate "the self-directed achievement of people with all forms of blindness" and increase public awareness about their strengths and capabilities.[2] Kish and his organization have taught a form of echolocation to at least 500 blind children around the world.[3] Kish, who has been blind and had to have his eyes removed before he was 13 months old because of eye cancer, is the first totally blind person to be a legally Certified Orientation and Mobility Specialist (COMS) and to hold a National Blindness Professional Certification (NOMC).[2][4] He also holds master's degrees in developmental psychology and special education from University of California Riverside.[2]

8. Frequency Determines Pitch and Amplitude Determines Loudness
Pitch - a measure of how high or low a sound is perceived to be, depending on the frequency of the sound wave.

9. Speed of Sound Depends on the Medium
Sound waves can travel through solids, liquids, and gases.
As sound waves create particle vibrations, the speed depends on how quickly one particle can transfer its motion to another particle.

10. Temperature of the Medium
As the temperature of the medium increases, so does the speed at which sound can travel through the medium
For example:
Medium
Temperature
Speed of Sound
Air
0 Celsius
331
25 Celsius
346
100 Celsius
366

11. The Doppler Effect Big Bang Theory Doppler Effect
Doppler Effect Explained

13. You should be able to answer the following…
How is frequency related to pitch?
What is the frequency range that humans can hear?
What are two animals that use frequencies outside of our audible range.
What is one thing you feel that you could now accomplish after learning about Daniel Kish and his journey?
As a dolphin swims toward a fish, the dolphin sends out sound waves to determine the direction the fish is moving. If the frequency of the reflected waves is higher than that of the emitted waves, is the dolphin catching up to the fish or falling behind?