Which test uses a bone oscillator to ascertain lateralization to the 'best cochlea'?

The Weber test is designed specifically to evaluate lateralization of sound perception between the two ears. In this test, a tuning fork is placed on the midline of the forehead, and patients are asked to report where they perceive the sound to be louder—in one ear or the other. The bone oscillator involved in the Weber test transmits sound directly to the cochlea, allowing assessment of which cochlea is functioning better.

When sound is perceived as louder in one ear, it typically indicates that the ear with the greater perception of sound may have better bone conduction ability, or that there is some conductive hearing loss present in the opposite ear, making the sound seem louder in the ear with normal or less affected hearing. Thus, it effectively helps in identifying issues with auditory function related to each ear.

This makes the Weber test distinct from other tests, such as the Rinne test, which compares air conduction to bone conduction in an individual ear, or the bone conduction test, which primarily assesses hearing ability through bone conduction rather than directly comparing the two ears. The pure tone test evaluates thresholds for different frequencies and does not focus on lateralization. Therefore, the Weber test is the correct choice when discussing lateralization to the 'best cochlea.'