How to Stop a Mac from Announcing the Timeby Brendan O'Brien
Mac computers are built with several user-friendly features. These features include the ability to announce the time. This can be great when you need to know what time it is to be able to meet a deadline. If you do not like when it announces the time, you can turn the feature off.
Click the small "Apple" icon in the top-left corner of the desktop. Scroll down and click "Preferences."
Click "Date & Time" in the window that appears.
Remove the check mark next to "Announce the time after" in the window. Close the window.