By now you likely know that the voice behind Siri isn't just a robotic recording, it's the voice of a real human. Today happens to be Siri's birthday, but we have a little fun fact that was recently revealed by CNN.

Siri's voice in the U.S. belongs to a woman named Susan Bennett who recorded samples for the digital assistant before it was launched on the iPhone 4S two years ago. Oddly, Bennett wasn't even aware it was her voice that was going to be used, though she had acted for other digital assistant units in the past, including Tilly the ATM for First National Bank.

Apparently one of her friends approached her and inquired about the voice being used for Apple's Siri software, asking if it was Bennett. She paid a visit to Apple's website and realized that yes, it was her voice being used, though she had actually recorded the Siri responses six years earlier. Bennett told CNN she recorded for four hours a day for an entire month at that time, but didn't know who would ultimately end up using them.

The voice service has improved a lot during the past two years, though it's lagging behind Google in some ways at this point. In any case, happy birthday Siri!