Siri is one of the most highlighted features introduced in macOS Sierra. It does the usual things you would expect a virtual assistant app to do. Almost every command you can give Siri on your iOS device, you can give it on macOS Sierra as well. The one key difference is that you can’t invoke Siri by saying ‘Hey Siri’. Instead, you either have to click the Siri button in the Menu bar or you have to hit the keyboard shortcut Command+ Spacebar. If the default shortcut doesn’t suit you, or it interferes with an app or script you have installed, you can change it. Here’s how.
The ability to change the Siri keyboard shortcut is built right into Siri’s preferences. You do not have to install a third-party app to change it. Open System Preferences and click on Siri.
There’s a Keyboard Shortcut setting that shows you the default shortcut; Command Space. Open this drop-down and select the ‘Customize…’ option.
When you select ‘Customize…’ from the drop-down menu, you will go into shortcut record mode. Any combination of keys you press will be recorded as the keyboard shortcut to invoke Siri. Type the shortcut you want to set and you’re all done.
Siri will now work through the new shortcut you’ve set. We should mention that you should not try and assign it a shortcut that is in use by the OS. For example, do not assign the Command+Shift+3 shortcut, which is reserved by the system for taking screenshots, to Siri. If you do, the shortcut itself will stop responding. Siri will never respond to it period.
Set something that you know won’t interfere with your other apps or the OS. You must use one of the special function keys i.e. Command, Alt, and Shift. You can combine it with any of the letter or number keys on your keyboard. If you do want to invoke Siri with the ‘Hey Siri’ command, there’s a little Dictation hack that lets you do just that.