Signaling is the establishment and use of an ideomotor sign.
This can be a nod of the head, movement of the hand, or even moving the fingers upwards.
The aim is to obtain an automatic response (yes, no) that is not consciously controlled.
This ideomotor response is often independent of the rest of the trance state.
It is sufficient to simply announce beforehand that the movement will be carried out by the body, an inner part, the subconscious, the superconscious, superego or any other choice (depending on the technique used).
The advantage of signaling over speech is that talking tends to make the subject
out of trance while finger movements, for example, do not require conscious effort.
Apart from the fact that the subject may be so far into a trance that they no longer feel any desire to speak at all.