Neurophysiology and special senses: middle ear impedance matching: practice question

A Physiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Physiology · Neurophysiology and special senses: middle ear impedance matching

Sample item

Sound passing from air to cochlear fluid would mostly be reflected if it were not for the middle ear. Which feature chiefly overcomes this mismatch?

ALarge area ratio of the tympanic membrane to the oval window, with ossicular leverageBAmplification by outer hair cellsCResonance of the external auditory canalDPressure equalisation by the Eustachian tube

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Large area ratio of the tympanic membrane to the oval window, with ossicular leverage

Air and cochlear fluid differ greatly in impedance. The tympanic membrane is much larger than the oval window and the ossicles act as a lever, so pressure is concentrated and sound is transmitted efficiently into the cochlea.

Option by option

A. Large area ratio of the tympanic membrane to the oval window, with ossicular leverage (correct)
Correct. Concentrating force on the small oval window and ossicular leverage match impedance.
B. Amplification by outer hair cells
Outer hair cells amplify the response within the cochlea and do not match impedance.
C. Resonance of the external auditory canal
Canal resonance gives modest gain at certain frequencies and does not solve the mismatch.
D. Pressure equalisation by the Eustachian tube
The Eustachian tube equalises pressure and does not match impedance.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Physiology question

What is the answer to this Physiology question?

The best answer is A, Large area ratio of the tympanic membrane to the oval window, with ossicular leverage. Air and cochlear fluid differ greatly in impedance.

Why is "Amplification by outer hair cells" not the answer?

Outer hair cells amplify the response within the cochlea and do not match impedance.

Why is "Resonance of the external auditory canal" not the answer?

Canal resonance gives modest gain at certain frequencies and does not solve the mismatch.

Why is "Pressure equalisation by the Eustachian tube" not the answer?

The Eustachian tube equalises pressure and does not match impedance.

What concept does this question test?

It tests Neurophysiology and special senses: middle ear impedance matching in Physiology. The tympanic membrane is much larger than the oval window and the ossicles act as a lever, so pressure is concentrated and sound is transmitted efficiently into the cochlea.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Neurophysiology and special senses: middle ear impedance matching?

For each system, sketch the key graph (pressure–volume loop, oxygen dissociation curve, nephron handling) and explain it aloud. Then use the flashcards and the other Physiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.