The sense of direction changes from time to time. Right now I think it's from outside the sliding glass door, which is to my right (sitting here on the couch).
But the sound is sometimes different, as though to remind me of other similar "droning" type sounds: a leaf blower (I hear them here when the landscapers come by weekly). A chain saw, and a wood chipper (I heard these when they cut back the trees a couple of different times since I moved here, one time fairly recently). A generator.
G to G#, and all around these two notes.
So, I guess I have "meditation induced tinnitus."
Makes it sound like a medical condition. Something that is bad, and worse than unnecessary. Something that needs to be treated, stopped somehow.
But if it really is a spiritual thing, then it isn't bad. It teaches me. And it communicates with me.
I will write some more on how.