Why does my Mac not speak after sleep?

macOS & Mac Apps

Hi all. This happens randomly, so I can't know what causes it. I usually leave my Macbook pro in sleep, open it, do what I need then close it again. Sometimes, when I am on the password field, there is no speech. I try to turn off then back on voice over, no luck. The only thing that fixes this is to completely hard shut down, then restart. It's not an ideal fix, I know that. I just don't know why nine times out of ten, it works fine then once in awhile absolutely no speech. I can enter my password, and it looks as though the computer works, but no sound of any kind. I haven't done anything differently. Thanks for any suggestions ideas, or if by chance someone has this happen too.