Audience's noise-reduction technology.
Here's why the iPhone 4 did not get Siri (and won't get it)
One of the biggest selling points of the iPhone 4S - except for the amazing 8-megapixel camera and dual-core processor - is Siri, your humble virtual voice assistant. And for many who are not perfectionists about photography, having Siri on the more affordable iPhone 4 could steer them away from the iPhone 4S.
But Apple has not brought Siri on the iPhone 4, and despite Cupertino not giving an official explanation, there’s one possible reason we haven’t looked at before.
Linley Group analyst Linley Gwennap looked at how big the A5 chip on the iPhone 4S is and concludes that the extra area on the die is used by Apple for integrating noise-reduction technology. A dedicated chip by start-up Audience allows the phone to pick up voices more accurately. For example, iPhone 4 noise reduction technology only made it possible for the phone to register voice when placed directly near the user’s mouth.
So basically, it all boils down to Siri not being able to hear you well on the iPhone 4.
"This situation helps explain why Apple does not offer Siri as a software upgrade on the iPhone 4. Although the older phone includes an Audience chip, the company has since improved its technology to handle 'far-field speech,' which means holding the device at arm's length rather than directly in front of the mouth," Gwennap explained.
Audience’s second-generation technology making all this possible was only launched in 2011, which explains why it’s not in the iPhone 4.
What’s interesting is that a new and better, third-generation Audience noise-reduction technology is on its way and might arrive on the iPad 3 or next iPhone. Apple is not Audience’s only customer, though - Samsung, HTC, LG and Sony are all on the list of companies using it. Handsets like the Samsung Galaxy S II, the HTC Titan and the Sony Tablet S come with the Audience chip.