This isn't anything to do with having "high standards" and having "sensitive ears". I have a congenital bisensinaural hearing impairment of moderately severe to severe nature (if you were to pit it in percentages, 85% loss in left ear, 65% loss in right ear) and I depend on hearing aids just to have a face-to-face conversation with people (even then I have a hard time understanding folks though I hear them just fine), let alone be able to work. I rely on devices that have good volume and clear modulation, which are STILL far and few in between and often expensive (insurance almost never covers anything hearing-related).
I have been interested in iOS devices because they have several features for people with disabilities such as me. The iPhone 4S-my first iPhone (I've had an iPad for almost 2 years) was reported to be significantly louder than the 4, so I thought to check it out. Phones go through rigorous testing with me, with and without wearing my hearing aids (as well as with and without their Bluetooth connectivity). In the Sprint Store, I found the volume to be satisfactory in all cases except for when placing the phone up to my ear while wearing a hearing aid (that is, assuming I didn't have/not using the aid's Bluetooth connecting device hanging down from around my neck), which requires special positioning so the solution for that is to use the speaker. I bought the iPhone 4S.
Well after I got home (1.5 hours/75 miles north of the store, which is the closest to me), I began to notice the voice feedback loop echo. VERY annoying and making it very difficult for me to understand the person I'm talking to. This occurs in all cases, including using plug-in wired earphones, my hearing aids with and without their Bluetooth connectivity and both speakers on the phone. Strange that this was not present at the store, otherwise I wouldn't have bought it. I tried different things to no avail. My research has yielded that this is a commonplace problem and certainly one I've rarely encountered in cell phones or cordless phones in the past. Still, I kept trying to work my way around it and hope that a fix could be had, including tips from other owners and Apple/Sprint, plus replacing my iPhone with a new one twice (from different stores...went to the nearest Apple Store in Portland, on the other side of the mountains 3.5 hours/100 miles away...which proves to me it isn't a "bad batch" problem). Sadly, the 14 day return period went by quickly during which I had hoped to resolve the issue vs the driving distances trips (I don't go that far JUST for one thing only) vs work schedule, etc.
The problem persists, though SOME calls aren't nearly as bad as others, fortunately. Oddly enough. I've never had anyone complain to me that THEY were hearing echoes during calls, but they haven't mentioned it perhaps thinking it was related to their equipment or the connection. I LOVE the iPhone 4S (I gave my HTC EVO 4G-which never once had an echo or voice feedback loop echo issue-to my sister) for its many cool and handy features, as well as being in the same ecosystem as my iPad. However, I'm sorely disappointed in the call quality-which is actually quite good-because of this issue. I love Apple and my experience with the company and its staff has been top-notch. But, to be honest, for them to continue ACTING like the problem is something that doesn't exist is disingenuous. "We're now aware of this and are working on it"-at the least-would be acceptable.