According to our sources, Apple had originally planned to incorporate what appears to be a second microphone in the recent version of the iPad mini.
The photo’s below shows the prototype iPad mini with an extra hole centered atop the rear of the device. It is unclear as to why Apple withheld the second microphone from the final product release, my guesses would be that it was axed out to cut down on cost, or to be preserved for a future generation iPad mini.
The current generation iPad mini only features one microphone on the the top of the device. Current generations of the iPhone have a second microphone that is used to improve audio quality during phone calls, shooting video, and using Siri, so it doesn’t make much sense for Apple to neglect that feature on the current generation mini.
The interesting thing about this leak is that many of the Chinese cases sold on amazon still feature this extra hole, which can mean that Apple decided to remove the additional microphone pretty close to the release date of the iPad mini. Usually prototypes and shell models are stolen by Foxconn workers and sold to Chinese case manufactures for upwards to 38,000 RMB (about $6000 USD).