Sound waves and hearing

• What are sound waves primarily composed of?

  Vibrations passing through molecules
• How do sound waves travel through materials?

  By causing particles to vibrate
• What type of wave are sound waves classified as?

  Longitudinal waves
• What are compressions in sound waves?

  Regions where particles are closest together
• What are rarefactions in sound waves?

  Regions where particles are furthest apart
• How do sound waves travel through solids?

  By causing particles to vibrate and collide
• Why do sound waves travel faster in solids?

  Particles are more densely packed
• In which medium do sound waves travel slowest?

  Gases
• Why can't sound travel through a vacuum?

  There are no particles to vibrate
• What happens to the frequency of sound waves when they pass between different mediums?

  It remains unchanged
• What happens to the wavelength of sound as it speeds up?

  The wavelength increases
• What happens to the wavelength of sound as it slows down?

  The wavelength decreases
• What phenomenon occurs when sound changes speed between mediums?

  Refraction
• What is the effect of hard flat surfaces on sound?

  They reflect most sound waves
• What are the main parts of the human ear?

  Ear canal, eardrum, ossicles, cochlea
• What happens when sound waves reach the eardrum?

  They cause it to vibrate
• What are ossicles?

  A group of three small bones
• What does the cochlea do?

  Converts vibrations into electrical signals
• How does the brain interpret sound signals?

  As sounds with varying pitches and volumes
• What is the typical human hearing range?

  20 hertz to 20,000 hertz
• How does aging affect hearing?

  Hearing range normally decreases
• What causes the decrease in hearing range with age?

  Wear and tear of cochlea and auditory nerve
• What are the key processes involved in human hearing?

  • Sound waves travel through the ear canal
  • Vibrations hit the eardrum
  • Vibrations transmitted through ossicles
  • Vibrations reach the cochlea
  • Cochlea converts vibrations to electrical signals
  • Signals sent to the brain via auditory nerve
• What are the properties of sound waves as they travel through different mediums?

  • Speed increases in denser mediums
  • Wavelength increases as speed increases
  • Frequency remains constant
  • Sound can be refracted, reflected, or absorbed