Ear and audiology: middle ear impedance transformer: practice question

A ENT 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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ENT · Ear and audiology: middle ear impedance transformer

Sample item

The middle ear overcomes the impedance mismatch between air and cochlear fluid. What is the approximate overall transformer ratio?

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

The answer and the reasoning

C. 22 to 1

The areal ratio of the drum to the stapes footplate is about 17:1 and the ossicular lever ratio is about 1.3:1, giving about 22:1. Without this gain there would be a loss of about 28 to 30 dB. This explains the maximum conductive loss caused by ossicular discontinuity.

Option by option

  • A. 100 to 1

    This overestimates the mechanical gain.

  • B. 5 to 1

    This is far below the combined effect.

  • C. 22 to 1 (correct)

    Correct. 17 multiplied by 1.3 gives about 22.

  • D. 1 to 1

    A ratio of 1 would mean no transformer action.

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.

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Questions about this ENT question

What is the answer to this ENT question?

The best answer is C, 22 to 1. The areal ratio of the drum to the stapes footplate is about 17:1 and the ossicular lever ratio is about 1.

Why is "100 to 1" not the answer?

This overestimates the mechanical gain.

Why is "5 to 1" not the answer?

This is far below the combined effect.

Why is "1 to 1" not the answer?

A ratio of 1 would mean no transformer action.

What concept does this question test?

It tests Ear and audiology: middle ear impedance transformer in ENT. 3:1, giving about 22:1. Without this gain there would be a loss of about 28 to 30 dB. This explains the maximum conductive loss caused by ossicular discontinuity.

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 Ear and audiology: middle ear impedance transformer?

Learn tuning fork results and audiogram patterns by sketching them. Then use the flashcards and the other ENT 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.