I stumbled across the following this morning by chance, and thought of this thread (aspects of the “eight positions of mastery” in DN 33 were puzzling me, still do, so I went to the Kasina section of the Vimuttimagga hoping for insight, and in another tangent ended up in the section with this quote). It is, at least in the eyes of a relative novice like myself 
, a very interesting tidbit of information regarding the jhānas (it may well already be known to most of you guys, but new to me anyway). If I’d found this in the Patisambhidamagga, it really would have been the perfect quote. It’s only from the Vimuttimagga though. Hope that’s still allowed! 
MISCELLANEOUS TEACHINGS
I further elucidate the meaning of the above.
Q. What are the miscellaneous teachings in the field of concentration?
A. Stoppage of sounds; overturning; rising; transcending; access; initial application of thought; feeling; uncertainty. “Stoppage of sounds”: In the first meditation, jhāna, speech is stopped. On entering the fourth meditation, jhāna, the yogin stops breathing. Gradual stoppage of sounds: When the yogin enters into concentration, he hears sounds, but he is not able to speak because the faculty of hearing and that of speech are not united. To a man who enters form concentration, sound is disturbing. Hence the Buddha taught: “To a man who enters meditation, jhāna, sound is a thorn”. “Overturning”: A man, concentrating on the earth kasiṇa develops earth perception through non-earth perception.
I’m using the pdf version of the Vimuttimagga at: http://urbandharma.org/pdf1/Path_of_Freedom_Vimuttimagga.pdf (this quote comes from p.184 of the PDF or p.120 using the original page numbering of the book itself).
It drives home to me again how flimsy is the raw evidence underlying all the various viewpoints on jhāna given the sparsity of source data. The nice thing about the above quote was it provided an interesting perspective to me on how the somewhat puzzling reference to “speech” in SN 36.11 for the first jhāna might work in conjunction with the reference to “sounds” in the Thorns Sutta AN 10.72.
To quote the most relevant bits of SN 36.11
Then, bhikkhu, I have also taught the successive cessation of formations. For one who has attained the first jhana, speech has ceased. For one who has attained the second jhana, thought and examination have ceased. For one who has attained the third jhana, rapture has ceased. For one who has attained the fourth jhana, in-breathing and out-breathing have ceased.
…
Then, bhikkhu, I have also taught the successive subsiding of formations. For one who has attained the first jhana speech has subsided…. For one who has attained the cessation of perception and feeling, perception and feeling have subsided. For a bhikkhu whose taints are destroyed, lust has subsided, hatred has subsided, delusion has subsided.
…
There are, bhikkhu, these six kinds of tranquillization. For one who has attained the first jhana, speech has been tranquillized. For one who has attained the second jhana, thought and examination have been tranquillized. For one who has attained the third jhana, rapture has been tranquillized. For one who has attained the fourth jhana, in-breathing and out-breathing have been tranquillized.
There’s much in common there with AN 10.72, though some interesting differences in content and emphasis. I must admit I had thought that the most natural and likely reading, though not inevitable, in AN 10.72 of sounds being a thorn to the first jhāna was that hearing was simply suppressed and verbal processes shut down in some kind of connected/parallel sense (though I remained non-committal and open-minded on the other senses).
There seems to be, at first glance to me anyway, a rather different viewpoint inherent in the above segment of the Vimuttimagga. Rather a different picture of the role of sound as a thorn is being portrayed; sounds as a thorn seems to be implied as a kind of side effect of the suppression of the speech faculty. So stoppage of hearing, yes, in this interpretation is implied but perhaps more gradually, though presumably still completely by at least the fourth jhana, where breathing has to have stopped in both sutta accounts (is a thorn in AN 10.72) to enter the fourth jhana.
When a single short segment like this in a later commentary can be a important data point, IMO it hammers home to me how little there seems to be to work with in terms of raw material in this topic. Interesting earlyish alternative perspective though.
There’s definitely plenty of food for thought in the Vimuttimagga too, e.g. five step version of the usual four jhanas that links each step to suppression of one of the five hindrances, and takes on vitakka vicāra amongst other things. New and exciting to me but probably old hat to most of you!
