sound waves and hearing

• What are sound waves primarily composed of?

  Vibrations that pass through the molecules of a medium
• How do sound waves travel through materials?

  They travel as a series of compressions and rarefactions
• What are compressions in sound waves?

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

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

  By causing particles inside the solid to vibrate and collide with neighbors
• Why do sound waves travel faster in solids than in gases?

  Because the particles in solids are more densely packed
• Why can't sound travel through a vacuum?

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

  The frequency does not change
• What does the equation speed = frequency × wavelength imply when sound speed increases?

  The wavelength must increase if the frequency remains the same
• How does the wavelength of sound change in higher density mediums?

  The wavelength gets longer as sound speeds up
• What happens to the wavelength of sound in low density materials like air?

  The wavelength gets shorter as the sound slows down
• What phenomenon occurs when sound changes speed as it moves from one medium to another?

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

  They reflect most of the sound, creating echoes
• What are the main parts of the human ear involved in hearing?

  • Ear canal
  • Eardrum
  • Ossicles (three small bones)
  • Semicircular canals
  • Cochlea
  • Auditory nerve
• What happens when sound waves reach the ear?

  They travel along the ear canal and hit the eardrum, causing it to vibrate
• How are vibrations transmitted from the eardrum to the cochlea?

  Through the tiny bones called ossicles
• What does the cochlea do with the vibrations it receives?

  It converts the vibrations into electrical signals
• How does the brain interpret the electrical signals from the cochlea?

  As sounds, with higher frequencies interpreted as higher pitches
• What is the typical range of frequencies that humans can hear?

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

  The range of hearing normally decreases due to wear and tear
• What are the key points about sound wave transmission and human hearing?

  • Sound waves are vibrations traveling through a medium.
  • They consist of compressions and rarefactions.
  • Sound travels faster in solids than in liquids and gases.
  • Sound cannot travel through a vacuum.
  • Frequency remains constant when sound changes mediums.
  • Wavelength changes with speed in different mediums.
  • Human hearing involves the ear canal, eardrum, ossicles, cochlea, and auditory nerve.
  • Humans can hear frequencies from 20 Hz to 20,000 Hz.