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 transmit through solids?

  By causing particles to collide and vibrate
• 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 change mediums?

  Frequency remains the same
• What happens to the wavelength when sound speed increases?

  Wavelength must increase
• What happens to the wavelength when sound slows down?

  Wavelength gets shorter
• 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 the eardrum to vibrate
• How does the brain interpret electrical signals from the cochlea?

  As sounds with varying pitches and volumes
• How are vibrations transmitted from the eardrum?

  Through the ossicles to the cochlea
• What does the cochlea do with vibrations?

  Converts them into electrical signals
• What is the typical human hearing range?

  20 hertz to 20,000 hertz
• What causes the decrease in hearing range as we age?

  Wear and tear of cochlea and auditory nerve
• How does aging affect human hearing?

  Hearing range normally decreases
• What are the key processes involved in sound wave transmission?

  • Sound waves are vibrations through a medium
  • Travel as compressions and rarefactions
  • Speed depends on particle density
  • Sound can be refracted, reflected, and absorbed
• How does the structure of the ear contribute to hearing?

  • Ear canal directs sound waves
  • Eardrum vibrates in response to sound
  • Ossicles transmit vibrations to cochlea
  • Cochlea converts vibrations to electrical signals
  • Auditory nerve sends signals to the brain