Delete Siri and Dictation history on Mac
When you turn on Siri or turn on Dictation, you can choose to share audio recordings of your Siri and Dictation interactions on your Mac with Apple.
Your requests are associated with a random identifier, and not with your Apple ID. You can delete request history—both audio recordings and transcripts—that is associated with a random identifier and less than six months old (you must be connected to the internet).
On your Mac, choose Apple menu > System Settings, then click Siri & Spotlight in the sidebar. (You may need to scroll down.)
On the right, click Delete Siri & Dictation History.
Important: Deleting Siri and Dictation history doesn’t change the choice you made about sharing audio recordings. To change that setting, see Change Privacy & Security settings.