This sounds like it has the teensiest bit of wind-like background sound, which my rumble doesn't have, but otherwise it's pretty accurate. I was actually thinking about trying to recreate the sound using myNoise.net, but you beat me to it.
This is the book i started with. Don't let the buddhist cover fool you, it is very secular and matter of fact. It is very logically laid out, you might read a section, have a question about the section, the see it answered in the very next section.
This book is more of a tome than the first but it is a real gem. I think the amazon reviews can say more about it than I could but i have read close to a hundred books and this is by far the most thorough, complete, and distilled form of knowledge on the topic i have found, and it is heavily supported by current peer reviewed research and delves into the topic of consciousness in very cool ways. Again don't let the cover fool you. This book is concerned with one thing, efficacy, and seperates the dogma and symbolism from old teachings into easy to read and effective
I am a sound designer too, and did create this tool, to create you own :
This is a great way to puncture an ear drum. They have little bottles of alcohol at the pharmacy/chemist that will dry out ear fluid. Brand doesn't matter, just make sure it's got >90% alcohol. You can also use plain alcohol at that percent if you have an eye/ear dropper handy.
The little bottles are great if you swim often and tend to get water stick in your ears.
If it's a wax issue, here are the Mayo clinic recommendations.
I'm hard of hearing and need to wear hearing aids. You don't want this if you can help it.
Also flat earthers were a pre-1930s cult-religious phenomenon in Zion Illinois, where they amassed plenty of "evidence." That all died out before WWII, when the cult leaders were caught draining megabucks out of their Believers. I recall that they tried to build a gigantic carpenters' level, in an attempt to prove that Lake Michigan was truly flat! (Once a meme has proved its power, any charismatic idiot can harness it again and again.)