What is the primary role of outer hair cells in the cochlea?

The primary role of outer hair cells in the cochlea is to amplify sound vibrations. Outer hair cells are specialized sensory cells that respond to sound stimuli by changing their length in a highly coordinated manner. This motility enhances the movement of the basilar membrane, subsequently amplifying the sound vibrations that enter the auditory system.

This amplification is crucial for our ability to hear softer sounds and is a fundamental element of the cochlear amplification process. The outer hair cells help to increase the sensitivity and frequency selectivity of the inner ear, allowing for a wider range of audible sounds. Their role enhances the performance of the inner hair cells, which are responsible for converting these amplified signals into electrical impulses that are sent to the brain for processing.

In contrast, the other options do not accurately reflect the primary function of outer hair cells. While vibrations are detected and transmitted through the auditory system, the specific amplification function of outer hair cells is essential for effective hearing. Balancing sound frequencies is also not a primary function associated with outer hair cells; rather, this involves complex processing performed by various structures in the auditory pathway.