Sound
- 1. Sound
- 2. Introduction • Sounds are vibrations that can travel through different materials. • The pitch of a sound is how high or low the sound is. • The loudness of a sound is how loud or soft it is.
- 3. Sounds & Vibrations • Sounds are made when objects vibrate. The vibration makes the air around vibrate, and the air vibrations enter your ear. You hear them as sounds. • You cannot always see the vibrations, but if something is making a sound, some part of it is always vibrating.
- 4. Sound travels through materials • Sounds as vibrations can travel through many different materials. • Sound can travel through solids, like metal, stone and wood. • Sound can travel through liquids, like water. • Sound can travel through gases, like air.
- 5. Sound travels through materials • Sound vibrations travel better through some materials than others. For example, sound vibrations travel very well along metal pipes. • Sound cannot travel through a completely empty space (a vacuum), which has nothing, not even air, in it. If there is a vacuum between a sound-making object and our ears, we won't be able to hear the sound.
- 6. Pitch of Sound • The pitch of a sound is how high or low the sound is. A high sound has a high pitch and a low sound has a low pitch. • A short string gives a higher-pitched sound than a long string when they are plucked. • A tight drum skin gives a higher- pitched sound than a loose drum skin.
- 7. Loudness • The loudness of a sound is how loud or soft the sound is. • A guitar string plucked strongly makes a loud sound. A guitar string plucked gently makes a soft sound. • A drum skin hit hard makes a loud sound. A drum skin hit gently makes a soft sound.
- 8. Loudness • Loud sound • A recorder blown hard makes a loud sound. • Soft sound • A recorder blown gently makes a soft sound.