Transition in and out of sleep often produces a wide variety of sensory experiences from several to one modalities. Most frequent, as in the case of my spouse, is auditory sounds. People will frequently hear their name called out or hear a loud clashing sound or a mild whisper. Knocking and loud bangs are also fairly common.
In my case I typically see down a fleeting, extending corridor. The images are sometimes clear, sometimes darkened, and as I become aware of them they disappear. Usually this is in color, but occasionally black and white. Once in a while they are very vivid hallucinations I can recall shortly after wakening, but usually not.
Thought processes on the edge of sleep tend to differ radically from those of ordinary wakefulness. For example, something that you agreed with in a state of Hypnagogia (excellent read) may seem completely ridiculous to you in an awake state. On a different direction though, many (including myself here) are able to solve problems in this state. Edison, Tesla, and other inventors have reported ideas or problems they have solved in this condition. The brain is fascinating!
Also, research has shown that during the hypnagogic state subjects are very open to suggestion and EEG readings show elevated responsiveness to sound around the onset of sleep.
Hypnagogic state is also frequently re-created with the use of psychedelic pharmacology. Very similar findings across the spectrum between near sleep and drug induced experiences create these visionary experiences.
Hypnagogic phenomena may also be interpreted as visions, OBE’s, astral glides, prophecies, premonitions, apparitions, or enlightenment, depending on the experiencers’ beliefs and those of their culture.
There are some famous hypnogogians who “heard” the voice within themselves; Abraham, Noah, Muhammad, Moses, Paul, Joseph Smith and so on. Happy to be living at a time where we have valid explanation for hallucinatory experience that precludes sleep. If there is a god, he’s right between your ears. It is us. Top that off with a little peyote or LSD and you’ve got yourself a church.
WARNING: Images can be quite complex and detailed, and may not make any sense. Enter Religion