Rinne’s test is negative if minimum deafness is –
**Core Concept**
Rinne's test is an important clinical tool used to assess the integrity of the middle ear and the vestibulocochlear nerve. It compares the air conduction (AC) of sound to the bone conduction (BC) of sound in the same ear. A negative Rinne's test indicates that bone conduction is better than air conduction, which can be a sign of conductive hearing loss.
**Why the Correct Answer is Right**
In a negative Rinne's test, the patient is unable to hear a sound through air conduction that they can hear through bone conduction. This occurs due to a conductive hearing loss, which can be caused by a problem in the middle ear, such as otosclerosis, a perforated eardrum, or a middle ear infection. When sound is conducted through bone, it bypasses the middle ear and directly stimulates the cochlea, resulting in better hearing in cases of conductive hearing loss.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because a negative Rinne's test is not associated with sensorineural hearing loss, which is characterized by damage to the inner ear or the vestibulocochlear nerve.
* **Option B:** This option is incorrect because a positive Rinne's test indicates that air conduction is better than bone conduction, which is the opposite of what is seen in conductive hearing loss.
* **Option C:** This option is incorrect because a negative Rinne's test is not a sign of normal hearing, which would be indicated by a positive Rinne's test where air conduction is better than bone conduction.
**Clinical Pearl / High-Yield Fact**
A negative Rinne's test is a key indicator of conductive hearing loss and should prompt further investigation into the middle ear for potential causes.
**Correct Answer:** C. Conductive hearing loss.