Change VoiceOver voice settings on Mac
Change the speaking voice used by VoiceOver, and settings such as rate or pitch.
Note: VO represents the VoiceOver modifier.
To hear the first setting, press VO-Command-Shift-Right Arrow.
Continue to press VO-Command-Shift-Right Arrow until you hear the setting you want to adjust.
To increase the setting’s value, press VO-Command-Shift-Up Arrow. To decrease the value, press VO-Command-Shift-Down Arrow.
The new settings are applied only to the default voice.
To customise voice settings for your default language and additional languages, open VoiceOver Utility (press VO-F8 when VoiceOver is on), click the Speech category, then click Voices.
When you install voices that are compatible with macOS, they are installed in /Library/Speech/Voices so they are available to all users of your Mac.
If you’re using portable preferences on a guest computer when you change voice settings, the settings are saved to the portable preferences drive and not to the guest computer.