In this subunit, students are not supposed to have any (formal) prior knowledge of the subject but some understanding of the concepts from their everyday life.

The activities in this subunit introduce students to the following concepts and ideas:

  • Sounds are produced by vibrating objects and vibrating columns of air.
  • Pitch and loudness are two characteristics of sound.
  • Changing the way an object vibrates can change the pitch or volume of the sound produced
  • Pitch is determined by the frequency and loudness by the amplitude of vibrations.
  • Sound is produced by human vocal folds as air moves through the tightened folds.
  • Sound requires a medium (for example, air, glass, metal, wood) to travel through.
  • Speed of sound is less than the speed of light.
  • The human ear has a membrane that vibrates when sound reaches it; the ear and the brain translate these vibrations into sensation of sound. Exposure to very loud sounds can cause damage to hearing.