sound occurs in my head
What does that mean exactly? Could you describe it? Does it sound like physically outside but you realize by logic that it "didnt happen", or is it clear right away that it's an imaginary sound?
What does that mean exactly? Could you describe it? Does it sound like physically outside but you realize by logic that it "didnt happen", or is it clear right away that it's an imaginary sound?
The sound does not feel dreamlike at all (like sounds you imagine while in a hypnagogic state.) I can imagine a first-timer might mistake it for an external event and rising in shock to look for the source of the disturbance.
The sound is of short duration (about 0.2s) and is loudest at the end of the sound, cutting off sharply into total silence ("...wwwWWWHOMP!") It's very loud, but not painful like a real report in a quiet room would be. The loudness feels like 120 dB or so. The sound is absolutely "pure," missing environmental cues like position, echo, and pressure. I perceive the location to be smack-dab in the middle of my head, not anywhere outside my physical body (a bit like headphones.) Because of this, and because I have been cued to the impending sound (see below), there is no danger of mistaking it for something real.
The chronology when my head goes boom:
T minus 30 seconds: I'm in bed, eyes closed. It always happens before or at the beginning of hypnagogia.
T minus 10 seconds: I get a feeling somewhat akin to a sudden pressure drop in my ears (but without any popping or physical symptoms). This is a cue that tells me to expect an explosion.
T: The pseudo-aural pressure cue suddenly ends by "transforming" into a short, explosive sound. Heart rate starts to rise rapidly. My eyes remain closed and my musculoskeletal system usually don't react, as the sound doesn't scare or surprise me.
T plus 5 seconds: Heart is beating as fast as it can go. At this point it feels almost exactly like right after snapping awake from a night terror, but without the fear component.
T plus 60 seconds: Heart rate begins to decline to normal levels.
To answer your question, it doesn't sound like it's in my head. It sounds as if I were to play someone screaming or buzzing over some headphones.