Learners often perform gestures incorrectly with unpredictable results. One common problem is for a stray extra finger to be added to the gesture. This seems to be particularly prevalent when users try to perform a two finger double tap and unintentionally perform a three finger double tap. A three finger double tap will silence VoiceOver speech and this can lead to serious confusion. I now often disable the three finger double tap gesture unless the user is likely to require this feature. It is simple to restore the gesture when the user is more confident performing gestures. By the way, if Zoom is enabled, you still need to remove the three finger double tap gesture, even though the gesture that turns off speech is actually a three finger triple tap. To disable a gesture, go to Settings/ Accessibility / VoiceOver / Commands / Touch gestures. For example to disable the three finger double tap gesture, scroll down to three finger double tap, which will be set to toggle mute. Double tap on this to open the list of actions that can be assigned to the gesture and scroll to the bottom of the list where you will find the remove button.