What's the mechanism for magically understood speech from the monk's Tongue of the Sun and Moon feature?

Question

The rules for the monk ability Tongue of the Sun and Moon state:

Starting at 13th level, you learn to touch the ki of other minds so that you understand all spoken languages. Moreover, any creature that can understand a language can understand what you say.
PHB, pp.79

How does the meaning get transferred? Some possibilities I've thought of:

1. The listener hears the words as the speaker forms them, and the meaning is sort of empathically transferred.
2. The listener hears the words in a language he understands, Star Trek style, without hearing any of the actual mouth-sounds.
3. When monk comes in contact with someone who speaks a language A, he rips the understanding of the language out of their mind and can thereafter actually speak A.
   • This is less likely, because it doesn't say that he gains the new language, as such. However, perhaps he gains only the spoken language, and not the written part.
4. The monk simply does understand all spoken languages after this level, and the bit about ki is just flavor text.

The first two answers imply that there needs to be another mind present who speaks A. The third implies that the monk at least needs to come across an A-speaker to understand it. The fourth implies that he can just speak and understand A upon leveling up.

I then have a follow up question, which might influence the way we think about the first one. The Magic Mouth spell (PHB pp.257) allows you to leave a message for others to hear, triggered by a circumstance of your choice. I think I'm in safe territory to say that the monk would definitely understand the message ("all spoken languages"). When the monk hears the message, how is he understanding it? The speaker's mind isn't there to be touched. Further, even if there's some magic hoodoo going on there, what if (and please do forgive me for going outside the setting, but I couldn't resist exploring the theory) he heard a radio, or a phonograph?

Along a similar vein, if (the gods only know why) you had a Monk 13/Wizard or Bard 3, and you cast Magic Mouth, could you specify that anyone hearing it would understand?

Summing up:

1. How does the monk communicate meaning?
2. Would the monk be able to understand a recorded message, where the one who left it might not even have a mind anymore?
3. Can the monk leave a fully understandable message?

I also asked this related question about choosing who gets to understand the monk.

Answer 1

[Ki] is an element of the magic that suffuses the multiverse—specifically, the element that flows through living bodies. (PHB 76)

In the context of the above statement, we should understand the term "spoken" in the Tongue of the Sun and Moon ability description to mean "sound created by a living being". This is reinforced by the claim that the monk learns to "touch the ki of other minds".

1. The monk communicates and receives these meanings by a sort of mental bridge between herself and the other creature. The speech is also occurring for the monk, but she has no automatic comprehension of it. This is also supported by the fact that written language is excluded; a piece of writing has no present mind to communicate it to the monk, and so she cannot read it.
2. No. A recorded audio message suffers from the same limitation as a written message: it is mindless.
3. No. The understanding is conveyed by the monk herself, and if she leaves, then the message is mindless. The spell Magic Mouth requires the monk to "speak the message". The monk is incapable of speaking the message in other languages, and as the spell is not a creature, it cannot understand the mind-speak that the monk uses to communicate to other creatures.

Answer 2

This seems to me to be a reference to esoteric concepts like the Akashic record, whereby an enlightened being can access the collective consciousness of all sapient beings. You're not contacting the ki of any one being, but the ki of all beings who have ever existed.

Using this interpretation, you'd hear the actual phonemes and understand their essential meaning through mystical empathy (and vice versa, when you speak).

The rules don't say that a mind who speaks the language must be present, so I'd say that a recording would work just fine.

The rules do read "what you say," so I'd rule that a magic mouth spell cast by a monk would not be automatically understood.

Answer 3

The general rule on languages (PHB p. 17):

Languages

By virtue of your race, your character can speak, read, and write certain languages.

This is the specific rule that the specific monk ability is augmenting - I don't think that there is a lot here for us but given that in D&D 5e, specific beats general, it is always good to go back to the most general rule and work up.

The rule you quote (PHB p. 79) is:

Tongue of the Sun and Moon

Starting at 13th level, you learn to touch the ki of other minds so that you understand all spoken languages.

Moreover, any creature that can understand a language can understand what you say.

Ad "ki" is a "mystic energy" (PHB p. 78):

Starting at 2nd level, your training allows you to harness the mystic energy of ki.

Short answer - whatever you want: its "mystic".

Slightly longer answer

There is no "flavour text" in D&D 5e - if its there its a rule. "you .. touch ... other minds so ... you understand all spoken languages"; in context this has to mean touching the mind of the speaker at the time - I don't think it can be stretched to mean that you touch all minds and gain all spoken languages. I also fail to understand what practical effect knowing a spoken language that isn't currently being spoken has.

Even longer answer

1. "any creature that can understand a language can understand what you say"; you say it, they understand it.

2. You "touch the ki of other minds". In context, I think this means that you touch the mind of the speaker. I would rule that the speaker in the situation that your are suggesting is the magic mouth spell which has no mind to touch and would therefore be untranslatable - sounds without meaning (which is what the mouth is doing) are not language. I would rule differently for message since your mind is physically present. For other spells: POA.

3. No, "what you say" means it must be you that is saying it.

Answer 4

Alright here is the deal. Tongue of the Sun and Moon is a Secret Language, learn-able and reproduce-able. Also there are many other ways to communicate with all things living (and non living!) using only a single or two languages and without being a monk. Here is how:

Logical Rule #1

Rule on Languages: "By virtue of your race [and it's learned/developed properties], your character can speak, read, and write certain languages."

Logical Rule #2 "Your background might give you access to one or more additional languages of your choice."

Logical Rule #3 "Some of these languages are actually families of languages with many dialects... Creatures that speak different dialects of the same language can communicate with one another.

Logical Rule #4 "With your DM's permission, you can instead choose a language from the Exotic Languages table or a secret language..."

Assertion 1: English definition of Tongue means "spoken language", making Tongue of Son and Moon a Language.

Assertion 2: secret, is anything that is intentionally hidden, or not commonly accessible, ie druidic (ritual/spoken), thieves cant (visual/subliminal dialect) OR in this case Tongue of Sun and Moon.

Assertion 3: "Ki is ONE element of the magic that suffuses all living beings--specifically the element that flows through living bodies."

Assertion 4: Ki and ki points according to the languages definition are not needed to use Tongue of Sun and Moon, therefore nullifying the argument that it is monk only ability. However Tongue of Sun and Moon does require you to "touch the Ki of other minds", in order to "understand all spoken languages" even though you do not need Ki necessarily to do so.

Assertion 5: Tongue of the Sun and Moon is not the only way to Access the "language of the mind", just as becoming a druid or being taught by a druid is not the only way to learn druidic.

Using logical deductive reasoning we see that the language of the mind is the master language from which all languages of living creatures, and their dialects, cants etc. were derived. The language of the mind is a LANGUAGE that is undiscovered, and unnamed and unknowingly accessed by the Language of Sun and Moon as well as potentially accessed in many other ways.

SO wrapping up we have discovered several important things:

1. The language of the mind is a hidden secret language. And all living creatures with minds have it flowing through them via the element of ki.
2. It is in fact so secret that D&D doesn't know that it has created it.
3. The language of the mind is not the languages name, thereby preventing us from picking or learning it as our default language directly because we are not SURE it exists or even how to know if it does let alone reproduce it, even though we see that we are accessing it's results through the secret monk language: Tongue of the Sun and Moon.
4. Tongue of the Sun and Moon is only one way to touch the ki of other minds.
5. Ki is the magical element that flows through the mind of living things.
6. Touching the Ki of other living minds is only one way to access this unnamed language of the mind.
7. Other elements of magic that suffuse the multiverse flow through non living things, giving access to the language of the mind possible by many other means.
8. Behind the language of the mind is the deeper hidden and undiscovered language of the multiverse, how all things (living and not) communicate/speak to each-other on a subatomic or magical level.
9. There are known ways to access the core language of the multiverse however there is no knowledge of what it is actually called.
10. With DM's permission starting players are allowed to pick secret languages as their background languages, this may include "Tongue of the Sun and Moon" or "Telepathy" as they are a discovered (in the handbook) secret language.
11. There are many other known ways to access the undiscovered languages of the living mind, non living mind, or multiverse, and I list many of them below.

I. DMs permission to acquire Tongue of Sun and Moon for starting language [access Living].

II. Monk level 13, acquire Tongue of Sun and Moon passively [access Living].

III. Create a half-everything race Ranger (8th quarter everything technically), choose your favored enemy to be Formian. This grants you the Hive Mind telepathic language that gives access to the minds of all your same race within 60 ft. Now you can Hive Mind (speak telepathically) with all races within 60 ft because you are technically all races [access Living].

IV. Create a Ranger, choose your favored enemy to be Dragon/Pseudodragon. This grants you Telepathy with any and multiple creatures that know a language that are within 60 ft of you [access Living].

V. Find a magic user, become transfigured into a dragon, or swap out your soul with a dragon, you can now speak telepathically with any living creature [access Living].

VI. Start the game as a rock or other inanimate object that. Hope a magic user transfigures you into a living creature. Learn common. Ask the DM if you can make a check to remember what it was like to be a rock. If Succeed. Make an intelligence check to remember if you could communicate with other inanimate objects. If Succeed. Make intelligence check to determine that method. If succeed. Use that new communication method to communicate with things in the same manner while in your new living form [access non Living].

VII. Become a high level magic user, make checks to create magic devices to discover a. all the elements of magic. b. the names of language of the living and non living minds. c. the name of language of the multiverse. Now make checks to create a magic device(s) that allows you to understand and speak with any creature, inanimate object, or the elements of magic, or the multiverse directly. [access all communication]

VIII. Become a high diety worshiper/patron. Build enough favor with your diety. Meet your diety. Ask your diety to grant you access to the secret languages of minds or the multiverse or to show you how to do so. [access all communication]

IX. Become a level 13 monk. Learn tongue of sun and moon. Get a mage to Transfigure a rock into a living being. Touch the mind of the newly alive being and learn to speak the language of inanimate objects in addition to living objects. [access living and non living]

X. Become a high level mage/scholar. Learn all languages. Increase your intelligence really high. Tell the DM you are rolling the remaining years of your characters life to discover the names of the hidden secret languages and reproduce their practical application. Ask the DM what you need to roll/how many times to succeed. If you succeed. DM has to tell you what it is(Make it up) and your character dies being remembered for the discovery. If you fail your character dies and is buried in an unmarked grave for wasted research. [access all communication]

Probably several other ways, those were all I could think of off the top of my head.