I’ve had them both while falling asleep and while waking up. It’s ranged from snippets of conversation to incoherant babble. It’s included things such as sudden, loud noises to melodic music. It’s a wonderful thing, I think.
Very easily a symptom of a sleep disorder called Narcolepsy.
The following are some symtpoms (you don’t have to have all of them to have narcolepsy)
- Dreaming while drifting off to - or coming out of sleep
- Hallucinations - often (but not always) “evil” in nature (usually going into or coming out of sleep) - including hearing sounds etc
- being paralised when you wake up
- feeling sleepy throughout the day
*experiencing sudden weakness - especially when laughing, crying or at other high emotion moments - inability to avoid napping
can be treated, you need to see a sleep specialist if you suspect you have it.
there’s plenty info online - google it 
I’ve heard it called Sleep Paralysis. It’s a theory that this may explain the Alien Abduction stories. I’ve experienced it myself - hear people, and saw 2 red glowing thingies…
Well I’m glad I’m not alone…unfortunately all I ever hear is that damn loud bang. Not hearing music or voices might tie in with the fact I almost never remember my dreams. (shrugs)
I get the odd hypnogogic hallucination too - a bang, someone calling my name, or sometimes the sensation of a bright light being shone at my eyelids. Thought I was going mad for a while until I found out what it was.
Sleep paralysis is a different thing - it’s one’s conscious mind waking up while the rest of the body is still asleep. It might coincide with hypnogogia, but it isn’t the same thing.
Sleep Paralysis is acutally the body not switching off the normal state of paralysis that occurs during REM sleep…it can happen in anyone but is very common in people suffering from narcolepsy (as mentioned above) - so it’s not really about the body still being asleep so much as still being in a state of paralays usually only associated with REM (dream) sleep.
oh…and in case anyone reading this experiences the very frightening sleep paralysis thing…I have heard (tho as i’ve never had sleep paralysis happen myself) from various individuals that it is possible to snap yourself out of it by rapidly moving your eyes back and forth. It can be a very frightening experience when it happens… because you literally cannot move any part of your body EXCEPT your eyes (remembering that it is associated with REM - Rapid Eye Movement - sleep this makes sense)
I often have what I’ve been told is sleep paralysis, but mine’s a bit different. I will wake up from a dream unable to move or breathe. I feel like I’m sinking into the bed and I sometimes have visions, ghostly transparent things. I have to use all my strength to pull up out of it. it’s really scary because it feels like I’m dead but in reality it only lasts a few seconds. Doctors have told me it’s perfectly normal and fairly common.
Oh and one thing, on the subject of auditory hallucinations, I once had a very strange experience with one. I was at home, alone, at the time and “heard” my friend saying that they screwed her high school yearbook picture up, and put the wrong quote under it or something, and she was upset about the trees. It was strange, and she wasnt talking to me, it was as if I overheard her telling someone else. Months went by and i never told her or thought much about it, but one day she called me and said “hey I just got my yearbook and guess what/” and I said “they put the wrong quote?” and she was like how’d you know? I told her “I heard you telling someone months ago,” and she said “but I didnt know until today.”
They also obscured part of her face with a picture of some trees. I suppose it’s just a weird coincidence but talk about weird…
Yeah, the same thing happens to me. I either hear 2-3 second clips of songs I’ve got stuck in my head or short clips of voices I’ve heard a lot lately.
Sleep paralysis is familiar for me too. That one isn’t so nice as hearing things as you fall asleep. Come to think of it, I’ve seen lots of strange things as I’m waking up regardless of if I’m paralyzed or not. Dark and shadowy sillouhettes, celebrities, evil children, ghosts…
I like having it though. It always means having a story to tell. 
Thumps, bangs and sounds like someone hammering wood are what I hear.
It’s kind of amazing that I stumbled across this thread this particular morning as the phenomenon was particularly strong overnight last night and this morning for me. The sounds actually jerked me back awake (or more slightly concious, I guess) because I was certain that they were real - they weren’t, the night was dead still and silent.
I’ve experienced hearing music as I’m drifting off to sleep a couple of times.
Sometimes, I’m lucid enough that I can realize the music is in my head and manipulate it. First I try to change the volume to verify that I’m in control. Then if that works, I’ll add other musical lines and instruments to the melody. Percussion, horns, keyboard, even singing.
There’s absolutely no way I can do that in a waking state, but I’ve created some damn nice music that only I’ll ever be able to hear.
My brain makes up songs while I’m asleep, but they’re not particularly great. They’re mostly Fred Penner or Raffi - style children’s songs with very simple rhyme schemes and a lot of “something something something” for lyrics where the subconscious composer hasn’t put in real words. I usually hear them as I’m waking up and they get stuck in my head.
I only hear weird noises in this state if there is already an everyday noise going on, and the noise needs to be constant. It doesn’t happen in a silent room.
Typically, it’ll happen if I’m trying to sleep in a train or aircraft. I find the steady noise of these modes of transport very conducive to sleep (which is maybe why some folks tune their TV to the noise of a dead channel for sleep). So I’ll be there half asleep, vaguely aware of the engine noise, when suddenly the noise gets extremely loud, as though the engines have surged. It’s enough to wake me up, and upon complete wakefulness, I know that the engines haven’t surged. It seems quite real though, and not at all dreamlike.
I’ve had experiences of trying to sleep on a plane where I’ve gone through this being woken by an inagined noise three or four times in several minutes, until I eventually give up and read a book.
Another weird thing I get sometimes is this: when I’m really sleepy but trying to stay awake, I’ll start to drift off, and a seemingly audible, electrical sounding snap in my head will wake me up. Usually this is accompanied by some sort of hallucinatory flash as well.
Those are fun too.
These experiences all happen during the hypnogogic state. Midway between sleep and awake. As you fall asleep, your body becomes paralysed (sleep paralyses) and your mind begins to enter a dream state. All variety of sounds and images can appear as the dream world is “constructed”.
A similar phenomenon occurs when one remains awake whilst the body falls asleep. The conscious interpretation of this is often like that of falling off a cliff or suddenly tripping, or being punched, a sudden loud noise, etc.
I will quite often hear faint voices, distinctly male but most definately not my own. I can’t quite ever make out what they say.
A couple weeks ago, I was laying in bed sick with a fever and I just finished watching an episode of Alias that I had downloaded on my computer. I drifted off into a weird state, it felt like I was awake, but in retrospect, I was probably having sleep paralysis. I suddenly came under the notion that I was some kind of special agent and the fate of the world was hindering on whether I moved or not (or something to that extent I dont exactly remember). I was scared to death, it felt like I was wide awake and I actually believed that the world would end if I didn’t have some specific breathing pattern and if I couldn’t hold still. Very weird. I actually wish I could remember it better.
That sounds more like fever-induced delirium to me. Used to get it all the time when I was a kid. Scary sh*t.