Bhikkhu Anālayo tries to prove one can not hear sounds in four jhānas

Moggallana hears sounds in imperturbable samādhi

Bhikkhu Anālayo’s analysis on Moggallana hearing sounds in imperturbable (anenja) attainment is seriously flawed.
anenja is ambiguous.
It usually means the formless attainments,
but it can also refer to fourth jhāna.
It's only by context we can make an educated guess whether it means
1) only formless atainments
2) only 4th jhāna
3) both 1) and 2)
Bhikkhu Anālayo does dutifully acknowledge the possibility of the 3rd option,
but he doesn't make full disclosure and justify this important assumption,
like an objective person should do.
Here's the reason that's important.
The Theravada EBT is unambiguous about the formless attainments, having transcended form (the body sensations, ability to hear, see, smell etc.), one is not able to hear sounds.
For example, in Theravada EBT
MN 43 mind divorced from 5 body faculties can know the first three formless attainments.
AN 9.37 mind divorced from 5 body faculties stated different way
(What is one percipient of when divorced from 5 sense faculties?)
Answer is same 3 formless attainments as MN 43, plus na ca sa-saṅkhāra-niggayha-vārita-gato
The Theravada vinaya and commentaries, and the other EBT vinayas, seem to be in agreement on formless attainments, are only pure if they can't hear sounds.
This being the case, by deduction it's almost for certain Moggallana's imperturbable samādhi is referring to case (1), only formless attainments.
If you examine all the passages where case (2), only 4th jhāna, is meant by 'imperturbable', most famously the often occurring pericope of the purifed fourth jhāna. With bright workable mind, which can easily access the supernormal powers, divine ear, etc, obviously if you can levitate, hear sounds from miles away, from other worlds and any distance, then you're not in a state where you can't hear sounds.
So given those constraints, you could deduce with 99% certainty that the vinaya passage with Moggallana must be referring to formless attainments. We can't be 100% sure, but if you're going to argue for case (3) then you have a duty to disclose you're making an unlikely assumption and why you are doing that.
Bhikkhu Anālayo conveniently avoids mentioning all of this. Why? Confirmation bias most likely. You want to prove you can't hear sounds in the four jhānas, so you manufacture evidence, cherry pick passages, then use a biased sample fallacy to support your cause. But is it possible he just didn't do his homework and think things through?
Let's look at the conclusion he arrives at. Bhikkhu Anālayo concludes Moggallana was in fourth jhāna, and therefore since he heard sounds while in fourth jhāna, and the Buddha called it 'impure', then a proper fourth jhāna means you can't hear sounds.

cherry picking the four jhānas

Now that he's "proven" that in a proper fourth jhāna, one can't hear sounds,
he then sets out to cherry pick passages between Agamas and Theravada to prove that in a purifed, proper version of the second and third jhānas, one can't hear sounds.
Since I don't read Chinese, I wouldn't be able to do a proper analysis on the feasibility of his arguments.
But if we restrict our discussion to just Theravada,
I've done a detailed study of this in a separate article here, with pāḷi+english audit.
Also included in that same article is Ṭhānissaro Bhikkhu's excellent essay on the same subject, "silence is not mandatory".
See ☸4nt → 8aam #8: Sammā Samādhi 🌄 →You can hear sounds in the 4 jhānas.
http://lucid24.org/sted/8aam/8samadhi/sound/index.html
for detailed sutta references and explanation.