HACKER Q&A
📣 behnamoh

Why does “Hey Siri on my iPhone” activate Siri on my iPad?


I have multiple Apple devices with Siri enabled on all of them. But I don't know why we can't ask Siri on any specific device to activate itself. Whenever I say "Hey Siri", it activates on a random device. For example, at my Mac, it opens Siri on my iPhone which is farther away. It should be fairly easy to implement a feature that activates Siri on any specific device. Or am I missing something?

  👤 SpikeDad Accepted Answer ✓
It's not a random process but it's not documented that well by Apple. All of the devices logged into your Apple ID do a quick handshake amongst each other via Bluetooth to determine who's going to respond to "Hey Siri". Generally it's the closest (since distance is something BT 5.0 can calculate) but there are some rules to determine who's going to answer.

There is some priority for example a device recently raised responds first - this is often your iPhone. The Mac is low on the priority - HomePods are usually highest. Amongst HomePods it's usually the one that hears the command first or at the loudest volume. You can remove your iPhone from the pool by placing it face down.

Devices can't be selective based on the audio because they're not analyzing the commands until they're actually activated. The always running Secure Enclave waits to match the voice pattern "Hey Siri" without the device knowing anything at that point. That's why Apple can say the devices are not listening or recording - they don't wake up and start listening until the Secure Enclave tells them to wake up. I believe however the devices keep a short amount of audio so that they can roll it back after they actually are activated.

I do agree with you in principle however that Apple should figure out some way for users to prioritize various devices. You can of course turn off "Hey Siri" responsiveness but there should be a bit more to it.

👤 MBCook
It’s not random (in theory). They’re all listening and pick up on the command. They talk to each-other and quickly decide who can hear you best and that device is the one that that responds.

It doesn’t sound like it’s working well (or at least predictably) for you.

I keep it off on all but my watch (only on raise) and my HomePods. I trigger the other devices manually by holding the appropriate button.

If Siri worked better with between devices stuff, e.g. “start a 10 minute timer on my watch”, I wouldn’t have had to do that. Some things work like “start The Simpsons on Hulu on TV” but so many don’t.