I only found one solution - will this help?
Pause or resume speech
To pause or resume speech on your Mac, do one of the following:
Press the Control key.
When the VoiceOver modifier is the Caps Lock key, press that key.
Mute speech
To mute speech on your Mac, do one of the following:
Press VO-Command-Shift-Right Arrow until you hear Volume, then press VO-Command-Shift-Down Arrow repeatedly to lower and eventually mute VoiceOver.
Open VoiceOver Utility (press VO-F8 when VoiceOver is on), click the Speech category, click Voices, then select Mute speech.
If you move the VoiceOver cursor after speech is paused, VoiceOver begins speaking the item that’s in the VoiceOver cursor.
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