Flash the screen for alert sounds
Your computer will play a simple alert sound for certain types of messages and events. If you have a hard time hearing these sounds, you can have either the entire screen or your current window visually flash whenever the alert sound is played.
This can also be useful if you’re in an environment where you need your computer to be silent, such as in a library. See Choose or disable the alert sound to learn how to mute the alert sound, then enable visual alerts.
Open the Activities overview and start typing Accessibility.
Click on Accessibility to open the panel.
Select the Hearing section to open it.
In the Visual Alerts section, switch the Visual Alerts switch to on.
Under Flash Area, select whether you want the entire screen or just your current window title to flash.
You can quickly turn visual alerts on and off by clicking the accessibility icon on the top bar and selecting Visual Alerts.