Sound Waves and the Ear (HT only) (physics only)

• What type of waves are sound waves?

  Longitudinal waves
• How do sound waves cause particles to behave?

  They cause particles to vibrate parallel to wave direction
• Through which mediums can sound vibrations travel?

  Solids, liquids, or gases
• What does the speed of sound depend on?

  The medium through which it travels
• What is the speed of sound in air?

  About 330 meters per second
• Why can't sound travel through a vacuum?

  There are no particles to carry vibrations
• What detects sound in humans?

  The human ear
• How do sound waves enter the ear?

  They enter the ear canal and vibrate the eardrum
• What do the three small bones in the ear do?

  They transmit vibrations to the cochlea
• What do electrical signals from the cochlea do?

  They pass through the auditory nerve to the brain
• How is sound interpreted in the brain?

  As sound
• What stimulates the cochlea?

  Sound waves transmitted by the bones
• What range of frequencies can humans typically hear?

  20 Hz to 20,000 Hz
• What is the unit of frequency measured in?

  Hertz (Hz)
• What is the range of normal human hearing?

  20 Hz to 20,000 Hz
• What does a limited range of frequencies mean for hearing?

  Humans can only hear certain frequencies
• What is the upper limit of normal human hearing?

  20,000 Hz
• What is the lower limit of normal human hearing?

  20 Hz