Which tuning fork test result indicates conductive hearing loss?

The tuning fork test that indicates conductive hearing loss is when the Weber test lateralizes to the affected side. This lateralization occurs because, in cases of conductive hearing loss, the sound is not transmitted effectively to the cochlea in the affected ear. As a result, the sound appears to be louder in the ear with the conductive issue, as the brain receives a relatively greater signal from that side due to the bone conduction being more effective than air conduction.

In conductive hearing loss, the ability of air conduction (AC) is particularly diminished, while bone conduction (BC) may still be relatively intact or perceived as better since the vibrations are transmitted directly through the skull to the inner ear. Thus, the Weber test provides a quick clinical evaluation indicating the side of hearing loss by assessing lateralization of the sound perceived by the patient.

Other test results, such as Rinne's test showing AC greater than BC on the affected side, would indicate normal hearing or sensorineural hearing loss, not conductive loss. Similarly, statements regarding Rinne's results indicating BC over AC on the unaffected side do not reflect conductive loss in the affected ear.