From the early days of implants in the 1970s and the 1980s, speech perception via an implant has steadily increased. Many users of modern implants gain reasonable to good hearing and speech perception skills post-implantation, especially when combined with lipreading. However, for pre-lingually deaf children the risk of not acquiring spoken language even with an implant may be as high as 30%.[https://journals.sagepub.com/doi/abs/10.1177/0142723719834102] One of the challenges that remain with these implants is that hearing and speech understanding skills after implantation show a wide range of variation across individual implant users. Factors such as duration and cause of hearing loss, how the implant is situated in the cochlea, the overall health of the cochlear nerve, but also individual capabilities of re-learning are considered to contribute to this variation, yet no certain predictive factors are known.