Heh, you must be tired of my questions but here goes another…:
When I’m doing MILD, and trying to fall sleep…I hear a surprising sound that scares me…usually sounds most like a scream(short, like saying: “AH!”) but it’s loud and as I’m about to fall asleep, it scares me…
So, any idea of what this is??Is it good??
It is a HI (well techinally a HH since it is a sound). Yes it is good. That means you are about to go into a dream which could turn into a LD, if you don’t start off lucid.
Nice to know… 
i have them, never knew what it was till now… It changes from HI to HH to HI to HH again from time to time…
What else can it be, other than a LD, since i have 'em almost every night, but in the other hand, LD’s for me are somewhat rare? 
Of course not! If there were nobody to ask questions, there would be no need to create a forum!
It’s very funny that you hear such hypnagogic sounds while MILD’ing. Generally people may have them when they WILD. You could add what you hear to theList of WILD sounds. 
By the way, just look at this list, it’s interesting to read all the different sounds people can hear. Technically, HH are what Claude Rifat, a scientist who was interested in hypnagogia and altered states of consciousness, called “disattenuated thoughts”. The level of awareness to thoughts is attenuated during the waking state, so that we don’t confuse thoughts with physical sensations. This attenuation is removed while falling asleep.
Everybody has HH when falling asleep but we most often are not aware of. On the other hand, HH are not LD’s, that’s why having HH doesn’t mean you have LD’s. The scientist Alfred Maury used to study HH, yet he never had a LD and believed it was impossible.
As for me, I suppose that having frequent HH could mean that you reach easily a deep hypnagogic state. It’s interesting for MILD and autosuggestion techniques, cause I’ve the feeling that it’s easier to implant a suggestion when you’re closer to sleep. Above all, it’s interesting for WILD of course.
HH? That can be damn scary… that happens to me quite a bit. It happens most when i go camping… but only on the first night. It is the worst thing i can imagine to do with LDing… especially when you cannot escape mfrom it by waking up. Like me… i once had very bad HH, so i opened my eyes to escape it, but it was still there, and getting worse… that sentence i just said brings back very bad memories…
Yeah, I know…it’s strange because I think I’m doing MILD but instead I doing WILD…because I stay conscious by repeating to myself a few phrases…
Anyway, a day after my third HH sound happened…I had a LD!!! Or at least I think it was one 
it was pretty weird…maybe I’ll post it in the BIG “was this a LD” topic
I had the weirdest HH sound last night…or was it the nap this afternoon…can’t quite remember. In any case, I swore that I heard music coming through a radio. It was realy faint and staticy but, like looking at the megelennic clouds with the corner of your eye, as soon as I ‘accepted’ that the sound was there without ‘listening’ for it, it became much more clear and vivid. Of course, once that happened I HAD to try and listen to what the song was, and it degnerated back into static:neutral: . Strangely enough, the sound persisted, and I had a number of these back-and-forths with it. As a side note, I was trying to MILD, and it paid off a little early in the morning, but I guess I was WILDing a little.
As I was falling asleep one night, I entered into the hypnagogic state and heard an extremely loud, short sound. It sounded like an orchestra shock (the sudden burst of music that plays in a movie when, for instance, something scary pops up). It was so loud and startling that I bolted up and frantically looked around me to see where it came from. At first I thought it might have been a car accident outside, but I soon realized that it was just HH. The sound was so loud and distinct, though, that it took me a little bit to accept that explanation.
Am I the only person who thinks something else might be going on here? This happens to me constantly, and sometimes I can’t even fall asleep because it will happen several times in a row. I fall asleep, then I’m jolted awake by a quick loud noise, and it repeats again and again. It can lead to insomnia sometimes it’s so bad.
Makes me wonder sometimes if it’s REALLY just HH… or something else?
I’m contrary to your belief, cloudwave. I use this loud sound to enter dreams during WILD. Of course, the sound could differ from person to person, thus its significance might change as well.
Are you sleeping on your back? This is HH mixed with myoclonic jerks. It happens to some people sometimes. I suppose you could change your sleeping position.