I have an iPhone 4S which is 18 months old, outside of warranty, and one day, during a phone call the person on the other end couldn't hear me at all. I could hear them perfectly. The problem is persistent but unpredictable. I tried testing it with Voice Memos, made a couple recordings. On both tests the levels were very low and there was a regular clicking sound and a lot of static. I had saved on my iTunes some other recordings I made with my previous iPhone 3G which never had any sound problems. The difference between the two is shocking. Bottom line: the microphone is not working on my current phone as it should. I went to my local Apple store (Vancouver, BC, Pacific Centre) and they said they couldn't fix it. I was on the phone last week with Apple Tech Support for an hour. I did a full system re-install as a "new phone" and the problem persisted. I am halfway through a three-year contract (Fido Canada) under which I can't upgrade my phone. Today I called Apple again and they said the only thing they could do is "repair or replace" for $199. I have been searching various forums, eg. on Apple's website, MacRumours.com and looking at videos people have posted with DIY methods to fix this issue. I believe it is a common issue with both the 4 and 4S models, more common than Apple would like to admit. I'm looking for people who have had the same or similar issues with sound on their phone. There seems to be a wide range of problems with sound on this phone, with the speakers, and with the microphone. If anyone has more detailed technical experience with this issue I would be very curious to hear what they have to say. From the type of problems people are having I think the cause might be a poor physical connection between two components in the phone, but I am not an electronics engineer. I am interested in filing a class action suit against Apple addressing the poor quality standards of the microphone design on the iPhone 4/4S and holding them accountable for the poor design of this phone, and offering replacement phones to those who have had the misfortune to be affected by this issue. Any interested parties please reply, comment or private message me, as applicable. I am posting this in as many places as I can to see if there is a strong basis for a class action suit.