Don't know about the first one you described. But the high pitched one I believe to be the carrier wave as well. Usually for me it starts out lower then increases in pitch as I'm being launched.

I've also heard it form from the sound of my fan before. The sound of the fan started changing and then started increasing in pitch. It was a strange phenomenon because it was the fan, as it changed, it wasn't two sounds it was the one.

For me its tinnitus caused by the small increase in blood pressure, that warps as the audio hallucinations start, an internal noise with your mind to play with.

I do believe it can be used as a tool to delve deeper into the experience

For me it was an up and down frequency that i would describe as a warble. There were liquid drips like in a cave and the sounds of equipment you may find in a lab or something. But above all those sounds, the wave was loudest, it felt like a guiding sound; slow, smooth and steady with a low frequency when I "let go". Fast and chaotic with a high frequency; when I reached back for this world, thought of my body or thought I was in danger. Unexpected and quite extraordinary.

Me too! I describe it as oscillation or vacillation... but it's definitely a sonic pulsation which stems from a vibration which can only be heard when we each shift from the ordinary, relative perspective of Homo Sapiens Erectus... to the extra-ordinarily, expansive and most centered frequency of our own personal sphere of harnessed attention and conscious-awareness.

I use the term "harnessed attention" because without an effort to direct our intent towards this living, breathing miracle we call life and living, we are simply entities born to think and conceptualize, mere cause & effect, organic automatons... whereas we might awaken to this paradigm and taste freedom and open our ears, eyes, mind & heart.

Thus, we are crystallizing and intentionally focusing our attention to a singular point, upon this core, present moment. We then find symmetry within this universal expression of energy, we expand and rejoice in the sublime tone of the here and now, itself symphony of sounds and exquisite thought-forms blooming before our mesmerized, internal eye and heard singing/ringing within our inner spiritual ear.

It's the ultimate buzz!!!

Does this notion remind anyone of cymatics? That salt/sand & sound stuff & the patterns that they "snap" into at the right frequency?

Just a thought.

P.S. Sorry if it's been mentioned, I'd not read all the thread before I posted.
Yes, it felt THAT important

..seems to emanate from both inside and outside the head at the same time..grows in intensity..seems to 'modulate' (i.e waver, not completely fixed frequency) ..is most common prior to 'breakthrough'..

..i think it only happens above a certain dosage, and not in all people or at all times..

I've noticed this too - and there seems to be varying combinations of rhythms to different feelings and teachings... the language of these realms is fascinating

I love how many of these descriptions, when put together, form a more brod memory of the experience I've had. Much of the feelings and thought, had faded from my surface memory but remain with me, deeper. With every description I read, that is close to my own experience, I am returned a little more to the moment of discovery. It feels like we are connected, through common experiences. I am also amazed at the ability of some to put to words the feelings and thoughts they've had while in the moment of experiencing the spice. When attempting to recall where I was and what I felt in the moment, much of it falls from my grasp. Thanks for helping me to remember.

The first time I experienced the carrier wave it was incredible, all I know I said was "ohhh man here we go" and then POOF.

To me, it is identical to the pitch-shifting noise at the end of Welcome to the Machine.

6:40 to 6:45. Chills every time!

http://youtu.be/9qEsTCTuajE?t=6m39s