PRACTICE HEARING QUIZ: Bio L104, FALL 20121. Sound wave amplitude is measured in units of: Circle one Hertz (Hz) Photons Milliliters Decibels (dB) 2. Briefly describe a function of the human outer ear:3. Briefly describe the main function of the human middle ear :4. You would perceive a 2,000 Hertz, 80 decibel sound wave as _____________ than a 2,000 Hz, 30decibel sound wave. Circle one: louder higher pitched quieter lower pitched5. A 2,000 Hertz, 15 decibel sound wave ________ than a 100 Hertz, 90 decibel sound wave. Circle one:contains more energy, has higher amplitude, has lower frequency, has higher frequency 6. Consider the sound waves graphed below: SOUND WAVE A SOUND WAVE B i. Do A and B depict pure tones or complex tones? _______________ii. Which sound wave is of higher frequency ? (circle one)sound wave A sound wave B they have the same frequency 7. When a hair cell’s stereocilia are bent towards the tallest row, tip links are __________, and the hair cell’s plasma membrane is ____________________.a. stretched, hyperpolarizedb. stretched, depolarizedc. slackened, hyperpolarizedd. slackened, depolarized8. Which ear part transduces sound waves into changes in membrane potential?a. ear drumb. Ossiclesc. Pinnaed. Inner hair cellse. Outer hair cellsPressure9. On the diagram on an ear below, label the pinna, ear canal, ear drum, and cochlea (note that because this diagram is of a dog’s ear, the pinna is more furry and pointy than in humans, otherwise the structures look the same. 0.5 pts each 2 pts total). PinnaAnswer Key for PRACTICE HEARING QUIZ: Bio L104, FALL 2012, correct answers in bold1. Sound wave amplitude is measured in units of: Circle one Hertz (Hz) Photons Milliliters Decibels (dB) 2. Briefly describe a function of the human outer ear: - To direct sound waves to ear drum - To protect eardrum (or middle ear) by: a) by providing distance from the external opening3. Briefly describe the main function of the human middle ear : to transfer sound waves from air to the watery fluid of the inner ear4. You would perceive a 2,000 Hertz, 80 decibel sound wave as _____________ than a 2,000 Hz, 30decibel sound wave. Circle one: louder higher pitched quieter lower pitched5. A 2,000 Hertz, 15 decibel sound wave ________ than a 100 Hertz, 90 decibel sound wave. Circle one:contains more energy, has higher amplitude, has lower frequency, has higher frequency 6. Consider the sound waves graphed below: SOUND WAVE A SOUND WAVE B i. Do A and B depict pure tones or complex tones? pure tonesii. Which sound wave is of higher frequency ? (circle one)sound wave A sound wave B they have the same frequency 7. When a hair cell’s stereocilia are bent towards the tallest row, tip links are __________, and the hair cell’s plasma membrane is ____________________.a. stretched, hyperpolarizedb. stretched, depolarizedc. slackened, hyperpolarizedd. slackened, depolarized8. Which ear part transduces sound waves into changes in membrane potential?Pressurea. ear drumb. Ossiclesc. Pinnaed. Inner hair cellse. Outer hair cells9. On the diagram on an ear below, label the pinna, ear canal, ear drum, and cochlea (note that because this diagram is of a dog’s ear, the pinna is more furry and pointy than in humans, otherwise the structures look the same. 0.5 pts each 2 pts total). OUTER: direct sound waves  eardrum, protect eardrum by providing distance from external openingMIDDLE: transfer sound waves from air to the watery fluid of the inner earINNER: transduces sound waves into changes in membrane potentialcochleaear drumPinnaear