1. A sound is a wave and frequency determines pitch
In your mind what is sound?
Sound is an example of a mechanical wave and is produced by a vibrating object that travels through matter

2. A sound is a wave and frequency determines pitch
Like all mechanical waves , sound waves transfer energy through a medium
Sound waves are essentially vibrations
A vibrating object pushes and pulls on the medium and sends out waves in all directions

3. A sound is a wave and frequency determines pitch
Humans have a sound making instrument with a set of vocal cords within the voice box or larynx in your throat
The following steps are the way your body produces sound:
1. Your muscles pushes air up from your lungs and through the narrow opening between the vocal cords

4. A sound is a wave and frequency determines pitch
2. The force of air causes the vocal cords to vibrate
3. The vibrating vocal cords produce sound waves
The way the human ear is shaped makes it perfect to collect sound waves in the following ways:
1. Your outer ear collects sound waves and reflects them into a tiny tube called the ear canal. At the end of the ear canal

5. A sound is a wave and frequency determines pitch
Is a thin, skin like membranes stretched tightly over the opening , called the eardrum. When sound waves strike the eardrum, they make it vibrate.
2. The middle ear contains three tiny, connected bones called the hammer, anvil, and stirrup. These bones carry vibrations from the eardrum to the inner ear.

7. A sound is a wave and frequency determines pitch
3. One of the main parts of the inner ear, the cochlea contains about 30,000 hair cells. Each of these cells has tiny hairs on its surface. The hair bends as a result of vibrations. This movement triggers changes that cause the cell to send electrical signals along the nerves to the brain. Only when your brain receives and processes these signals do you actually hear sound.

8. A sound is a wave and frequency determines pitch
The reason you can’t see sound waves is that they are too small to see from one place to another.
When then the sound waves travel it travels at a back and forth vibrating motion.

9. A sound is a wave and frequency determines pitch
Sound is a mechanical wave and can only move through a medium that is made up of matter.
Sound waves can travel through air, solid materials, and liquid because all of these mediums are made up of particles. Sound waves can’t travel through a vacuum which is a empty space with very little or no particles.

10. A sound is a wave and frequency determines pitch
The speed of sound also depends on its medium.
Sound will travel the fastest through a solid and the slowest in a gas because of the particles in that medium.
Temperature can also effect the speed of sound. The higher the temperature the faster it will travel.

11. A sound is a wave and frequency determines pitch
When you listen to music you hear both high and low sounds.
The characteristics of higher or lower sounds is called a pitch
The frequency of a sound wave determines the pitch of sound you will hear.
A high frequency wave with short wave lengths such as the flute make a high pitched sound.

12. A sound is a wave and frequency determines pitch
A low frequency wave with long wavelengths such as a tuba make a low pitched sound.
The unit for measuring frequency and also pitch is hertz. A hertz is one complete wave, or cycle, per second.
The highest a human ear can hear is about 20,000 Hz per second which is also known as ultrasound

13. A sound is a wave and frequency determines pitch
Each musical instrument and each human voice has its own particular sound, which is called the sound quality or timbre.
Sound waves cause particles to vibrate through the air.
These vibrations have a frequency or number of cycles per second.
All objects have a frequency at which they vibrate called a natural frequency

14. A sound is a wave and frequency determines pitch
Resonance occurs when the strengthen of a sound wave combines with an objects natural frequency.
The Doppler effect is the change in perceived pitch that occurs when a object is moving such as an ambulance or a train.