**Core Concept**
Paracusis is a phenomenon where a person with a hearing impairment perceives speech more clearly in a noisy environment than in a quiet one. This is due to the brain's ability to compensate for the hearing loss by relying more heavily on auditory cues from background noise.

**Why the Correct Answer is Right**
When a person has a conductive hearing loss, such as due to otosclerosis or otitis media, the sound is not properly conducted to the inner ear. In a noisy environment, the background noise can help mask the deficits in sound conduction, allowing the person to perceive speech more clearly. This is because the brain is able to use the auditory cues from the background noise to help interpret the speech sounds.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because paracusis is not typically seen in sensorineural hearing loss, such as due to presbycusis or Meniere's disease. In these cases, the problem is with the inner ear or the auditory nerve, and background noise does not help to improve speech perception.
* **Option B:** This option is incorrect because paracusis is not related to the type of hearing aid used. While hearing aids can help to improve speech perception in noisy environments, paracusis is a specific phenomenon that occurs without the use of assistive devices.
* **Option C:** This option is incorrect because paracusis is not a characteristic of normal hearing. People with normal hearing do not experience improved speech perception in noisy environments.

**Clinical Pearl / High-Yield Fact**
Paracusis is an important clinical phenomenon to recognize, as it can help to differentiate between conductive and sensorineural hearing losses. By asking a patient with hearing impairment to repeat words in a quiet room versus a noisy room, clinicians can gain valuable information about the nature of the hearing loss.

**Correct Answer: C. Conductive hearing loss.**