This article is part of a publication called “Tranquillity’s Secret” which you came into at about page 600.
Perhaps there was something that attracted you to this article, and if so, a direct question might have been productive.
The author has and does imperience these states, and thus knows what he is talking about and has described all of this here on Medium. Just tap/click on the header or footer of the article to go to the publication homepage, where there is a brief overview of what this is, or click on something in the navigation line at the top of the article, just under the title.
I suggest starting at the “Proem” which provides a detailed explanation of what this effort is about, and the best way to understand “inner spontaneous sounds.”
If you just want to vet the author and his motives first, there is a sequence of five articles under the heading: “Who Dares To Say These Things?”
I am happy to answer any questions that may come up.