I experience both but mostly internal ones (my old pdoc called them pseudo-hallucinations). It started with me hearing external voices like people were in my bedroom when there was no-one in the house, and whispers which are these malevolent voices all talking negatively about me but far away so I can't hear them clearly. Then I started hearing these 2 voices internally talking about me and calling me names and telling me to hurt myself. Then those 2 voices became external too. I tend to get more external voices when I'm stressed and the whispers when I'm really stressed, which makes things worse as they freak me out the most.

*Willow*