Witchcraft question: when you speak out loud a spell... WHO are you talking to?

And WHO or WHAT manifests the spell to you?

Pan

To Me , And It Depends On What You're Saying .

When you speak... alone in the forest at night... who is listening?
YOU create entities with your mind and YOU give them power and YOU assign them tasks. Then later YOU carry out their instructions.

Generally in a spell you are raising or have raised energy, speaking out loud is merely a way to direct this energy to whatever the purpose of the spell is.

Some spells call upon Gods for aide, whether this is asking for the deities help in raising/directing the energy, or that the energy comes from the deity is the opinion of the individual practitioner.

Magic doesn't work on the outside world, it works on the magician.
I don't mean this to sound dismissive, I just want you to entertain this possibility.