A medium is used by the spirit people as a vehicle for communication between the two worlds. Onlookers assume that the medium is able to see the spirit person standing near them and can hear their voice speaking to them. Some mediums encourage this belief by saying things such as “I can see so-and-so standing by you” or “he is saying such-and-such.” This is not actually true.
Mental mediums perceive the spirit communicator inwardly. When we say we hear a voice, it is an inner voice that we hear. You may hear a tune inside your head or remember the voice of someone speaking–this is very similar to the way mediums hear the spirit. The name given for this type of spirit communication is clairaudience. Intuitive clairaudience is a subtle condition which can be described as listening-in to soundless words. The medium is aware of an impression of hearing, as word forms come into consciousness.
Similarly, a medium feel sensations when a spirit is communicating. For example, I may feel the physical conditions they had when on earth. I will sense which sex they are or get impressions of their personality. This sensing is called clairsentience. Finally, I may see mental effigies showing the events from the spirit person’s life, see their face, or perhaps see pictures of places that were important to them. This perception of images is usually called clairvoyance. (Strictly speaking, clairvoyance is defined by parapsychology as an aspect of extra-sensory perception in which an object or event are perceived without the use of the known senses.)