## **Core Concept**
Impedance audiometry, also known as tympanometry, is a diagnostic test used to assess the function of the middle ear. It involves varying the air pressure in the ear canal and measuring the movement of the eardrum and the reflexes of the middle ear muscles. The test typically uses a probe with multiple frequencies to obtain accurate measurements.

## **Why the Correct Answer is Right**
The correct answer utilizes a **226 Hz** probe because this frequency is most commonly used for tympanometry. The **226 Hz** frequency probe is specifically designed to detect changes in middle ear function by measuring the compliance of the middle ear system as a function of air pressure. This frequency is considered optimal for assessing the mobility of the tympanic membrane and the middle ear system's reflexes.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While other frequencies can be used in audiometry, **226 Hz** is specifically standard for tympanometry due to its sensitivity to middle ear function changes.
- **Option B:** Higher frequencies might be used in different audiological assessments but are not standard for impedance audiometry.
- **Option D:** Lower frequencies might not provide the optimal sensitivity for detecting middle ear function changes.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that **tympanometry** with a **226 Hz** probe is crucial for identifying middle ear problems such as otosclerosis, tympanic membrane perforation, or Eustachian tube dysfunction. This test is a valuable tool in audiology and otolaryngology for assessing hearing and diagnosing middle ear disorders.

## **Correct Answer:** .