Cochlear implants are considered to be one of the most significant technological achievements in the twentieth century for the treatment of deafness. Prior to the introduction of these implants, treatment options for profoundly deaf individuals included visual communication (lipreading or sign language), tactile devices, or reliance on amplification systems that provided limited auditory information. Cochlear implants enable most users to detect and recognize speech sounds across the entire speech spectrum even at very soft levels – a great improvement when compared to the limited information deaf patients receive with traditional hearing aids. This increased ability to understand speech has resulted in striking improvements in spoken language skills, academic and vocational achievements, and quality of life for profoundly deaf individuals. This lecture will discuss this amazing technology, including a description of the internal and external components of contemporary devices, outline the surgical procedures to place the electrode array in the inner ear, and present the outcomes obtained with current cochlear implant recipients.