Beta testers of iOS 9.1 have found that the iPhone 6 and iPhone 6 Plus will get an upgrade that will make the phones continuously listen to the user. The phones have a special co-processor that will continuously listen for the command 'Hey Siri'.
The phones are equipped with a new M9 co-processor that has a 'always-on' feature making the phone to continuously listen for commands. The feature was discovered by testers of iOS 9.1 beta and confirmed by Apple.
Previously Siri could only be called with 'Hey Siri' if the phone was connected to power, the energy efficient co-processor makes it possible to listen to the user all the time. The feature will learn to only listen to the voice of the owner of the phone.
Apple has stated that Siri will only compare sound from the environment with previously recorded commands and doesn't record anything besides that. Users can disable the feature if they don't want to use it.
Moto X smartphones feature a similar technology called Moto Touchless Control. This works also works with a co-processes with Motorola calls a " super low-power natural language. Also Intel Skylake CPUs have a feature that makes Windows 10 continuously listen for commands.
