Change Siri settings for accessibility on Mac
On your Mac, use Siri settings for accessibility to type your requests to Siri instead of speaking them. This feature can be useful if speech is difficult or you don’t want others to hear your Siri requests.
To change these settings, choose Apple menu > System Settings, click Accessibility in the sidebar, then click Siri on the right. (You may need to scroll down.)
Open Siri settings for accessibility for me
Type to Siri
Type your requests to Siri instead of speaking them.
If a headset with a microphone is connected to your Mac, Siri speaks your typed command.
Additional options, such as setting a keyboard shortcut to activate Siri, are available in Siri & Spotlight settings.
To turn off spoken responses from Siri, show what Siri says on screen, and show what you say to Siri on screen, choose Apple menu > System Settings, click Siri & Spotlight in the sidebar, then click Siri Responses on the right. (You may need to scroll down.)