The title more or less explains what you have here. Via PSFK, this is a collection of nine people who get cochlear implants and experience the sensory modality of hearing for the first time. Can you imagine? The video of Nikki is probably the most dramatic.
Here's another YouTube video explaining how these amazing cochlear implants work. This reminds me of that apparatus that lets people "see" with their tongues (here's yet another YouTube video). It's interesting to think about the potential of technology to repair or manipulate our senses. Will we eventually have artificial synesthesia? Or sensory "peripherals" like extra eyes? Or Avatar-style avatars? Probably.