How to use visual alerts in macOS 10.14 Mojave

Terminology:
‘Alt’ refers to the ‘Option’ key ( ⌥ )

If you have enabled ‘Use F1, F2, etc. keys as standard function keys’ under ‘Keyboard’ settings in ‘System Preferences’ then omit the ‘Fn’ key from the keyboard shortcuts shown in this article.

1. Open ‘Accessibility Preferences’: Apple Menu > System Preferences > Accessibility. (See the article Open Accessibility Preferences on this website for more information.)
2. In the left column of Accessibility Preferences, click on the ‘Audio’ item under ‘Hearing’ or press ‘Fn’ + ‘Ctrl’ + ‘F7’ (once or twice) to highlight one of the options for example ‘Display’ and then press the up or down arrow keys to select ‘Audio’.
   
3. Click the checkbox next to ‘Flash the screen when an alert sound occurs’ or press ‘Tab’ to highlight the checkbox and press ‘Spacebar’.
   
4. If you would like to see what a visual alert will look like when one occurs click the ‘Test Screen Flash’ button or press ‘Tab’ until it is highlighted and press ‘Spacebar’.
5. When you are happy with your settings click the ‘Close’ (red) button at the top of the ‘Accessibility’ window or press ‘Cmd’ + ‘W’ to close the window.

Note: If this does not work it could be because your computer settings are managed by someone else (an IT department or administrator for example). If this is the case you will need to contact them to access these settings or for further help.