Microphone doesn't work while recording video

I have the same problem. It's intermittent but it doesn't work more than it does work so it would be easy to replicate. Sometimes audio would record in and out in a single recording, sometimes nothing but hissing/static. I do not run a cover of any sort, and my fingers are not covering any holes.

My iPhone 4S fails and works exactly the same every time:

FAILS, with the phone on speaker, or with the camera recording video (front or back) no sound is captured.

WORKS, in all other situations and apps that I could think of that use the microphone such as

google, Voice Memo, Dragon Dictation, Vonage Extensions, Skype, and taking the phone OFF speaker holding the phone to my ear. And also select microphone key to voice input instead of typing whenever the keyboard is there (Mail, Notes, Reminders, Safari, Maps, google Maps, ...)

Based on that, my guess is it's not hardware.

I'm using a 4S (64GB) from Verizon. In the nearby Verizon store I was told to back it up, do a master reset (which wipes out the phone), and restore it from the backup. I called Verizon support today before doing this and got exactly the same instructions. That's what I did today and NOTHING GOT BETTER.

After reading several discussion boards I made sure that I was not blocking any of the holes (trying to be thorough). I do not use a cover.

I just thought to test FaceTime. Microphone FAILS again.

I wind up making a reservation at the Genius Bar. The tech was helpful, and said that my iPhone 5 was defective and issued me a replacement on a the spot. He also said he hasn't seen this problem yet eventhough there is a large amount of users with this symptom/behavior on the forums.

I had similar experience at the nearby Verizon store. I pay for insurance - so no additional cost or hassle, the phone is 19 months old. They overnighted me a replacement phone and I restored to it last night. It works properly.

I'm curious what the hardware failure(s) is(are), and what my cost would be without the insurance.

This is NOT a blocked microphone issue. This is a FLAW in the product. Too many people (inclding myself) are having this issue. Only 10 minutes spent on the forums will show this consistant flaw. Apple needs to figure out what is happening and offer us a real solution. Since I have discovered this issue, I have had many recordings ruined, inclding taking my 2 year old son on his first slide, his first kiddie-coaster, and the first time he has helped me squeeze fresh orange juice. Apple consistantly ignores design flaws and it's gettng old.

how did you fix it because i have the same problem