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

The primary function of outer hair cells in the cochlea is to amplify and shape sound. These specialized cells enhance the sensitivity and frequency selectivity of the auditory system. When sound waves travel through the cochlea, the outer hair cells change their length in response to sound vibrations, which amplifies the motion of the basilar membrane and improves the ability to hear faint sounds. This mechanical amplification is essential for the fine-tuning of sound, allowing us to distinguish between different pitches and intensities. This function is critical for normal hearing and plays a significant role in our ability to perceive complex sounds in various environments.

The other options reflect different processes occurring in the auditory system, such as signal transduction and neural signaling, but they do not encapsulate the unique role of outer hair cells in amplifying and shaping sound, which is indeed a crucial aspect of hearing.