The Always-On Microphone
By default, the iPhone continuously runs a low-power audio analysis algorithm in the background, constantly listening to the ambient noise in your environment for the specific phrase “Hey Siri.” If it detects those words (or something that sounds remotely like them), it instantly activates the microphone at full power and begins recording your speech. If you are having a conversation with a friend and the phone suddenly interrupts you from across the room, it is highly disruptive. If you want to use Siri but refuse to allow the device to monitor your environment 24/7, you must sever the voice trigger.
How to Turn Off the Hey Siri Trigger
You can permanently paralyze the background audio analysis daemon via the Siri & Search settings.
- Open the Settings app on your iPhone.
- Scroll down and tap on Siri & Search (or Apple Intelligence & Siri on newer iOS versions).
- Locate the menu option labeled Listen for (or “Listen for ‘Hey Siri'”).
- Tap on it and select Off from the list of options.
Manual Activation Only
The change takes effect instantly. The iPhone will completely terminate the background audio-listening daemon. The microphone is now physically inert while the phone is locked or sitting on a desk. You can still use the digital assistant, but you are now strictly required to intentionally press and hold the physical side power button to activate it. This guarantees that Siri will only ever listen to your voice when you explicitly and physically demand it, restoring absolute acoustic privacy to your environment.