Research progress and prospects of cochlear implant technology

Traditional cochlear implant systems depend on external devices and face challenges related to convenience, esthetics, and auditory performance in complex soundscapes. Recently, research has shifted from “functional substitution” to “functional enhancement” and “biological fusion.” However, most emerging approaches remain in the preclinical, prototype verification, or early clinical stages, lacking substantial evidence of clinical benefits. This narrative review examines research progress across five key dimensions of cochlear implants: The electrode interface has advanced from passive implants to dynamic, adaptive, and biologically active intelligent interfaces. Signal processing strategies are moving toward intelligence and physiological adaptation, with deep learning primarily used for noise suppression and coding optimization; however, clinical application is limited by real-time performance and individual variability. Bionic sensing aims to replicate the energy conversion mechanism between hair cells and the basement membrane at the signal source, currently focusing on laboratory prototypes. Optogenetics-driven optical regulation offers high spatial selectivity but remains in the early preclinical stage. The development of fully implanted systems emphasizes internal energy supply, ultra-low power consumption processing, and system integration, marking a significant engineering direction for making devices “invisible.” Each section of this article critically evaluates evidence maturity and transformation barriers, highlighting common challenges such as long-term biological stability, safety, energy consumption, and regulatory verification that must be addressed before large-scale clinical application. Future advancements will require collaboration among materials science, neuroscience, microelectronics, and artificial intelligence to create a two-way high-fidelity interface. The ultimate goal is not only to restore hearing but also to reconstruct a more natural auditory perception.