Mac speaks when I type - can't switch it off

Hi, I'm new to Mac and trying to deal with a problem that started this afternoon. Whenever I type, a voice tells me what I am typing. I have been into the Accessibility settings and Voice Over is switched off. Command+F5 also seems to have no impact.

Under Accessibility > Speech 'Speak selected text when the key is pressed' is also deactivated. I've tried activating it and hitting Option+Esc, but that also has no effect.

For now I've just muted the sound, but that can't be the solution. Would appreciate it if someone can help me out.

Thanks, Mark