Hi, I'm unsure if this is the right place for this post, but this occurs quite often for me. I use iPhone 6S with iOS 13.2.
VoiceOver speech may stop or fade out while reading text
VoiceOver speech may stop or fade out while reading text inserted into a text field using Dictation. This issue appears to be limited to that particular use case, and swiping or touching the screen will bring back speech as normal.
Bug First Encountered
Device(s) bug has been encountered on
How often the bug occurs
I have made some more testing, and the speech seems to work normally when I dictate with my device in silent mode.