Friday, February 19, 2010

Ears and Sound Waves Notes

- Ears help the brain collect and process sounds.
- Sounds are created by waves of vibrations that are carried
through the air and through other objects.
- The properties of waves include the following:
- amplitude (height)
- wavelength (distance between the peaks/crests
of each wave.
- Sounds become louder as the amplitude of a wave becomes higher.
- Frequency is the number of wavelengths in a given amount
of time and is measured in hertz.
- A hertz is a unit of sound, equal to a wave cycle from crest
to crest.
- The greater the number of wavelengths that pass in a unit of time, the more high pitched the sound.
- infrasound less than 20 Hz is a range of sound waves below the audible span for human hearing. Elephants can hear in these ranges! (these notes are based on that website information)

Study Questions for Quiz

1. What does Hz stand for?

2. What does Hertz mean?

3. Can elephants hear at lower frequencies than humans?

4. What is the difference between ultrasound and infrasound?

5. What is the difference between amplitude and wavelength?

6. How do atoms transport sound through air?