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.
