Multimedia Presentation
Changing sounds:
Answer Sheet
What is and how is sound made?
Sounds are made when something vibrates. It might be a guitar string
or a drum skin - or it might be the vocal cords in your throat.
How does sound travel?
Sounds as vibrations can travel through many different materials.
They can travel through solids such as metal, stone and wood. They
can travel through liquids such as water and they can travel through
gases such as air.
Preventing sound traveling
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.
Can you think of an example of a vacuum?
Space.
Side: 1 of 2
Multimedia Presentation
Changing sounds:
Answer Sheet
What is pitch and frequency?
A high pitch sound corresponds to a high frequency sound wave.
A low pitch sound corresponds to a low frequency sound wave.
The unit used to measure frequency is named Hertz
When plucked, a short string gives a higher-pitched sound than a
long string.
When banged, a tight drum skin gives a higher-pitched sound than a
loose drum skin.
Therefore, if a string or drum skin vibrates slowly (lower frequency),
making deep sounds - or quickly (higher frequency) - making high
sounds.
What effects how loud a sound is?
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.
A recorder blown hard makes a loud sound. A recorder blown gently
makes a soft sound.
Therefore, when the instrument vibrates very little - the sounds are
soft. Or they may vibrate a great deal - so that the sounds are very
loud.
Side: 2 of 2