**Core Concept**
Sensorineural (SN) hearing loss is characterized by impaired sound conduction due to damage to the inner ear or the auditory nerve. This type of hearing loss often affects speech discrimination and is commonly associated with age-related decline.

**Why the Correct Answer is Right**
The patient's proportionate speech discrimination indicates that the hearing loss is likely due to a **sensorineural** (SN) type, as it suggests involvement of the auditory pathway beyond the cochlea. This is in contrast to conductive hearing loss, which would typically preserve speech discrimination. The age of the patient further supports this diagnosis, as **presbycusis** (age-related hearing loss) is a common cause of SN hearing loss.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the clinical scenario described.
**Option B:** While otosclerosis is a cause of conductive hearing loss, the patient's proportionate speech discrimination makes this less likely.
**Option C:** Meniere's disease is a disorder of the inner ear that can cause SN hearing loss, but it typically presents with fluctuating hearing loss and vertigo, which is not mentioned in the scenario.

**Clinical Pearl / High-Yield Fact**
It's essential to note that proportionate speech discrimination is a key differentiator between sensorineural and conductive hearing loss.

**Correct Answer: C. Meniere's disease**