Apple's new Siri voice assistant is a really useful feature but a few improvements could be made. I have read several forums with users requesting continuous listening and I can hear the privacy critics howling already and it goes something like this:
"Coninuously listen??! But then Siri will know all about my planned defection to the Communists! Unacceptable."
All jokes aside, one of the biggest hurdles to using the assistant is getting Siri to begin listening. In order to signal to Siri that you want to give it a command you need to hold down the hold button for almost a second before the signature purple microphone appears. The old voice commands feature was activated the same way but it took much longer to activate. To a user like myself who used to ask my iPhone "What time is it" and "Call dad" Siri was a great incremental improvement.
The key word here is incremental, everything about Apple is slow and methodical. If they released all their good ideas at once they wouldn't be in business for very long. Every competitor would steal the ideas, improve them, patent the improvement and take market share. Apple's strategy seems to involve keeping their technologies highly patented and interdependent (there is so much about iOS that cannot be copied due to patents it makes me prefer Android less since Google has to engineer the round about way to do everything Apple holds a patent to)
Another long-term strategy Apple uses to steal market share is their product release schedule and secrecy. The next Apple release will probably be this fall and the iPhone 5 will most likely contain improvements to its camera ,the introduction of NFC and changes to the "beta" Siri. One of these features might be continuous listening.
It would be wise for Apple to release this as a hardware upgrade, if it is even technically feasible. Previously with the release of the iPhone 4 many users were upset that Siri would be an iPhone 4-only (and now 4s) feature.
I believe this was due to a higher quality microphone required to capture your voice accurately. Siri is a hardware and software technology, and continuous listening, if it is even technically possible, would require a hardware upgrade.
The phone might get a new low-power chip that is responsible for continuous listening, or perhaps they are looking to make changes in the power management chip used in the iPhone. Either way I'm pretty excited for the new technology, and hardly afraid of continuous monitoring by my phone.