This same noise was going off in my head at the peak of the most intense Pharmahuasca experience I have ever had. I compared it to my brain being overloaded and short circuiting. The way I have described it until now, is the sound of a million computers connecting to dial up internet. I loved it actually. One of my most memorable experiences.
Definitely dont think it could ever be explained though, in scientific terms.. Which it will quite possibly remain a mystery forever.
Im quite excited to have seen that others have experienced this, or similar to my experience as well.

I thought it was a very unique situation, and would never hear of it again.
n,n-DMT is so mystical, it seems to be one of the very few substances that many can experience literally some of EXACT same mysterious experiences. It is quite intriguing.
But yes, listen to Endlessness and his/her Endless expertise, as n,n-DMT should never be in your thoughts of concern, really the worst you could have happen as an effect of it, is fear or anxiety on the come up of an intense experience.

So you are in the clear.
In fact, since that experience, being that it was one of the most self concluding, beautiful, longest lasting, dreamy experience of my life, it has made me entirely grateful from that day on. Ayahuasca will always be held in very high regards to me forever, and has for 10 years now, with the passion not subsiding in the slightest since I first came upon its wisdom.
May I ask you, what method of consumption of this DMT, did you experience this sound? ie. smoking, ayahuasca, etc.
Thanks for posting this.
To be honest when I saw the title of this thread, I thought, come on... Not another thread like this... Then I looked at what you originally posted and saw that it was far beyond the normal "Will DMT Kill me?!" or "Brain is ruined because of DMT now" or "Severe depression, hatred, anxiety after DMT" nonsense. Its a very unique situation, and I am glad you brought it to the forum, and gave others a chance to also indulge in their experiences being similar.

Quite exciting actually.
Thanks.
Peace and Love you, and may the Spice guide your spirit.
Take Care.