Why Siri is Exclusive to the iPhone 4S (And Why Apple’s A5 Chip is So Big)

Posted in Apple News, iPhone on 06/02/2012 by J. Glenn Künzler


Many have questioned Apple’s decision to make their Siri technology exclusive to the iPhone 4S. Most people assume it’s merely a tactic to get more people to buy the 4S, but CNET points out that the real reason might lie within the actual circuitry of the device.

CNET‘s Stephen Shankland reports:

Apple’s A5 processor includes noise-reduction circuitry licensed from a start-up called Audience, and a chip analyst believes that fact resolves an iPhone 4S mystery and explains why the iPhone 4 lacks the Siri voice-control system.

Audience revealed details of its Apple partnership in January, when it filed paperwork for an initial public offering (IPO) of stock. Teardown work from iFixit and Chipworks revealed a dedicated Audience chip in the iPhone 4, but the iPhone 4S integrates Audience’s “EarSmart” technology directly into the A5 processor, the company’s S-1 filing said.

The information is directly confirmed by Audience in their filing. Apple baked Audience’s “EarSmart” technology into their A5 chip, and agreed to pay royalties to Audience for the inclusion. Interestingly, the filing also suggests that only the A5 used in the iPhone supports Audience, while the A5 chip in the iPad 2 may not.

While the iPhone 4 also includes an Audience noise reduction chip, the company’s technology has only perfected their noise reduction at arm’s since developing their second-generation found in Apple’s A5 chip. This newer, more refined noise reduction is what allows Siri’s voice control and dictation to work so well.

There are still a few questions remaining, however, such as why the iPad 2 doen’t include Siri. Still, this is an interesting and somewhat plausible explanation for why Siri hasn’t made the rounds on older Apple devices.

  • IDon’tBuyIt

    thats why it works perfectly on my iphone 4 via Spire!!

  • It doesn’t work because apple don’t sign it. Stop just trying to find excuses for articles.


J. Glenn Künzler

Glenn is Managing Editor at MacTrast, and has been using a Mac since he bought his first MacBook Pro in 2006. Now he's up to his neck in Apple, and owns an old iBook, a 2012 iMac with an extra Thunderbolt display for good measure, a 4th-generation iPad, an iPad mini, 2 iPhones, and a Mac Mini that lives at the neighbor's house. He lives in a small town in Utah, enjoys bacon more than you can possibly imagine, and is severely addicted to pie.