Throughout the show, Daphne speaks without even a trace of a deaf accent, and has 100% speech discrimination-- she's able to talk to people without lipreading or even looking at them, and understands them perfectly all the time, even at a noisy college frat party. In reality, Daphne, would probably have a language delay due to the months she went without hearing, resulting in an increased likelihood of deaf accented speech. Further, the fact that she would've been implanted in the late 1990s would mean that her implant technology wouldn't have as advanced speech processors as exist today, making sound-only word recognition difficult, and nowhere near perfect. Check out this link to hear simulations of speech and musich through CIs with up to 20 channels. Even children implanted today (more than a decade after Daphne would have received her implant) with much more advanced technology and new speech processors do not necessarily achieve flawless speech or sound discrimination.
So why does it matter if TV misrepresents CI technology? It's just a fictional show, right? In part, it's such a big deal because Switched has been so accurate on other aspects of deafness, and its viewers have come to expect and trust that accuracy. After carefully building up their credibility, the series misused its authority and misled its viewers into thinking a cochlear implant is a quick fix. The fact that the show makes no mention of the hard work Daphne would have had to put into speech therapy and learning to listen through an implant just furthers the mainstream myth of this "miracle cure."
We love Switched at Birth, and we think it's a good idea to have a character with a CI on the show to demonstrate even more variation within the d/Deaf community, but we expected better. In the meantime, here's hoping some fans will do a bit of research on the subject.