There are people who can see UV. This can be a side effect of having certain parts of your eye removed during cataract surgery. So would not being able to see UV when some people can be considered a reduced sense or impairment? Most people would argue not. But it does make you think... What if non-deaf people got cochlear implants to hear better, or have more control over what they hear? If optic implants become common (or even wearables like Google Glass), would it be an impairment not to have them?
You could even go further, citing cell phones, warm clothing, SCUBA gear, and other technological advances as being "super powers," right? How far down does that rabbit hole go? When my friends pull out their smartphones to look something up on Wikipedia, I feel handicapped by my meager meatbrain. Yet I militantly choose to have a 2007 flip phone and deride people who insist on augmenting themselves like that. Call it meatbrain culture, I guess. Ironically, when I was given the opportunity to artificially improve my vision (glasses), I did it without hesitation.
I don't disagree that hearing is great (I'm a musician, so it's particularly special to me). But I don't think we should criticize parents who choose not to give their children superpowers or even normal powers. Bear in mind that cochlear implants are (or at least used to be) very invasive. A long time ago I used to volunteer at a deaf school, and it was obviously a struggle for the kids to get used to them. There was also risk of infection or other complications. I'm sure things have gotten better, but surgery is still surgery.