Hugh Pickens writes "Anna Leach reports that Siri support has been a contentious issue for owners of earlier iPhones, but a recent filing from Audience shows that Siri won't run on the iPhone 4 because the phone's chip can't handle it. Linley Gwennap of the Linley Group cracked one of the secrets of the new iPhone's A5 chip after working out that it packs some serious audio cleaning power not available on the iPhone 4's A4 chip. Audience has developed technology that removes most or all of the background noise when someone places a cell-phone call from a restaurant, airport, or other noisy location. The iPhone 4S integrates Audience's 'EarSmart' technology directly into the A5 processor, improving its technology to handle 'far-field speech,' which means holding the device at arm's length rather than directly in front of the mouth. Apple has also licensed the Audience technology for a 'new generation of processor IP,' which may mean that the forthcoming A6 processor will appear in the iPad 3 and iPhone 5. 'Why Apple has not simply purchased Audience is unclear. An acquisition would prevent Audience's other major customer, Samsung, from using the technology to compete with Apple,' says Gwennap. 'The company may be hedging its bets, as it could switch to Qualcomm's Fluence noise-reduction technology in the future.'"