ASVAB (Armed Services Vocational Aptitude Battery)Paragraph Comprehension (PC)Easy
Read the following passage: "The human ear is a remarkable organ capable of detecting a wide range of sound frequencies and intensities. Sound waves, which are vibrations in the air, travel through the outer ear canal and strike the eardrum, causing it to vibrate. These vibrations are then transmitted through a chain of three tiny bones in the middle ear: the malleus, incus, and stapes. The stapes, the innermost of these bones, presses against a membrane-covered opening called the oval window, which leads to the inner ear. Inside the inner ear, the cochlea, a fluid-filled, snail-shaped structure, converts these mechanical vibrations into electrical signals that are sent to the brain for interpretation." According to the passage, what is the primary function of the three tiny bones in the middle ear?
- ATo interpret sound frequencies and intensities for the brain.
- BTo transmit vibrations from the eardrum to the inner ear.
- CTo convert electrical signals into mechanical vibrations.
- DTo amplify sound waves before they reach the eardrum.
Show answer & explanationAnswer & explanation
Correct answer: B. To transmit vibrations from the eardrum to the inner ear.
The passage clearly states that the vibrations from the eardrum are "transmitted through a chain of three tiny bones in the middle ear" to the inner ear. This indicates their primary role is transmission.
Why the other options are wrong
- A. The brain, not the middle ear bones, interprets sound frequencies and intensities.
- C. The cochlea in the inner ear, not the middle ear bones, is responsible for converting mechanical vibrations into electrical signals.
- D. The bones transmit, not amplify, sound waves before they reach the eardrum; amplification occurs as part of the transmission but is not their primary location or action relative to the eardrum.
Middle Ear Ossicles Function
The three tiny bones (malleus, incus, stapes) in the middle ear amplify and transmit sound vibrations from the eardrum to the inner ear's oval window.
- Malleus (hammer), Incus (anvil), Stapes (stirrup)
- Smallest bones in the human body
- Crucial for efficient sound conduction
Memory trick: Outer collects, Middle moves, Inner interprets.