Yell "Hey, Siri!" on podcast — or out loud at an event — and you'll get dozens of complaints from people whose phones suddenly went into voice mode.

That might sound like an edge-case for Siri, Apple's personal digital assistant, but here's something more common — a family charging station with several iPhones devices plugged in. How do you target yours and yours alone? How do you make sure only your voice can activate Siri on your iPhone or iPad? On your Apple Watch? In your car or around your house?

To prevent false activations, the Apple Watch needs you to bring your wrist up and towards you before "Hey, Siri!" will work. The iPhone and iPad not so much. One way it could work is through voice biometrics. Think of it as a vocal fingerprint. Instead of Touch ID, think of it as Voice ID.

As the name implies, Voice ID biometrics could also be used for security the same way Touch ID biometrics are. Both our fingerprint and our speech patterns are "something we are". They can be used instead of passwords or passcodes, which are "something we know", or they can be used in conjunction for multi-factor authentication.

If you're a fan of the movie Sneakers, think of it as your voice truly being your passport.

I have no idea whether or not Apple plans to implement anything like this in iOS 9, of course, but the technology exists. Companies like Nuance are using it for a variety of applications already, and I'd love it if found its way into Siri one day.

You could register your voice the same way you register your fingerprint for Touch ID — by giving repeated samples.

The first time you hold down the Home button to activate Siri, it asks you to repeat a phrase, or several key phrases, three times each. Then it learns your voiceprint and the more you speak with it, the better than voiceprint gets. Again, just like Touch ID, but for your voice instead of your finger.

Voice ID could ensure that when someone yells "Hey, Siri!" on a podcast, or in a room with multiple iOS devices, only their Siri answers. Not mine, and not yours.

Voice ID could make it so that only you can access your iPhone or iPad or Apple Watch or CarPlay system or HomeKit system.

Voice ID could even load individualized environments when it recognized your voice — your preferences, your data, your content.

Biometrics wont solve all problems, of course. What if an iPhone, iPad, and future devices like a Siri-enabled Apple TV, all in the same room, are all yours? How would you target a specific device? "Hey, Siri on Rene's iPhone!" is workable but cumbersome. "Hey, iPhone!" locked to our Voice ID?

Taking existing technology and packaging it for the mainstream: These are the types of problems Apple is historically good at solving. Siri brought natural language voice control out of obscurity and onto hundreds of millions of devices. Thanks to its Pixar-like personality, we've learned to talk not only to it, but with it. And there's still a lot more Siri can do for us.

Siri has already made the microphone smart, the same way Touch ID made the Home button smart. But Touch ID also made the Home button personal. Voice ID could do the same for Siri.