Sounds can be soft like a whisper or they can be loud like an explosion. In the activity below you will investigate what makes sounds loud or soft.

Here are the answers to Activity 7:

• 1. a) The sounds ordered from softest to loudest are:

  1. Person blinking
  2. Person whispering
  3. Kettle boiling
  4. People talking
  5. Car starting
  6. Train passing by
  7. Explosion

• 1. b) Some sounds are louder than others because they are produced with more energy, causing larger vibrations (greater amplitude) in the air. These larger vibrations are perceived as louder sounds.

• 2. a) (This is an instruction for you to do.)

• 2. b) To make your voice louder, you push more air from your lungs, causing your vocal cords to vibrate with greater force and amplitude.

• 3. a) (This is an instruction for you to do.) When you hit a drum hard, you hear a loud sound. When you tap it gently, you hear a soft sound.

• 3. b) When a drum is hit hard it makes a loud sound. When it is hit gently it makes a soft sound.

• 4. a)

  • A (Cymbals): Can make a crashing, ringing, or shimmering sound.
  • B (Whistle): Makes a high-pitched, piercing sound.
  • C (Rattle): Makes a shaking, clattering sound.

• 4. b)

  • A (Cymbals): Hit them together with a lot of force.
  • B (Whistle): Blow into it with more force.
  • C (Rattle): Shake it vigorously and quickly.

• 4. c)

  • A (Cymbals): Tap them very gently or rub them lightly.
  • B (Whistle): Blow into it with very little force.
  • C (Rattle): Shake it very slowly and gently.