**Core Concept**
Audiometry assesses hearing function, with subjective tests relying on patient-reported responses. Objective tests measure physical parameters without patient feedback. Impedance audiometry evaluates middle ear function using pressure and movement, while subjective tests depend on patient perception.

**Why the Correct Answer is Right**
Impedance audiometry measures middle ear mechanics (e.g., tympanic membrane and ossicular chain movement) using tympanometry, detecting abnormalities like fluid or ossicular chain fixation. It does not require patient response to sounds and is purely objective. In contrast, tone decay, speech audiometry, and pure tone audiometry rely on patient feedback about sound perception—making them subjective.

**Why Each Wrong Option is Incorrect**
Option A: Tone decay requires patient reporting of sound perception over time, making it subjective.
Option C: Speech audiometry depends on patient’s ability to identify spoken words, which is a subjective report.
Option D: Pure tone audiometry involves patient indicating when tones are heard, thus being subjective.

**Clinical Pearl / High-Yield Fact**
Impedance audiometry is often used as a screening tool for middle ear disorders but is not a hearing sensitivity test—always perform it alongside subjective audiometry for accurate diagnosis.

✓ Correct Answer: B. Impedance audiometry