Abarim Publications' online Biblical Greek Dictionary
The noun ους (ous) means ear, the organ we hear with (not an ear of grain). There's also a diminutive form of this noun, namely ωτιον (otion), which specifically describes the auricle, the happy fleshy flap that forms the outer, visible part of the ear (see below for a further discussion of this word). That means that our noun ους (ous) describes the whole auditory system: the outer, middle and inner ear, plus all its physical and, importantly, intellectual functions.
The ear is not merely the organ we hear with, but much rather the organ that keeps us balanced, both in a vertical sense, by keeping us from falling over, and in a horizontal sense, by allowing us to home in on a source of sound. Our ears are conveniently located on the sides of our head, which suggests that evolution (or the Creator, if you will) greatly favored our ability to sense the direction from which a sound comes. This faculty obviously helps hunting, but apparently not so much that other mammalian hunters would also develop lateral ears. And that means that the position of our ears probably mostly helped in our social interactions: we humans are uniquely equipped to localize the source of a whisper on the other side of a crowded room (or a herd of wildebeests).
We humans hear in 3D, and unlike mammals with moveable ears, we have to move our whole head if we want to focus on a sound. That means that our eyes and noses automatically turn toward a sound that attracts us, resulting in a kind of hyper-vigilance that is guided by our auditory sense. Our eyes dart about independently, but our stereophonic ears direct the other senses toward an area that may not be immediately interesting to them, but will be interesting if the sound belongs to something significant and approaching. All this means that our ears are genuinely prophetic: they don't simply detect something before the other senses (because all senses do that; detection depends on the nature of the signal) but they are uniquely able to entice the other senses to turn into a direction that doesn't attract them.
The ancients understood that an individual human mind is self-similar to the whole of society (much in the same way that a distribution pattern on a recording screen is equal to the path integral of a single quantum particle). This suggests that of all humans, small selections have minds with pronounced "sensory" abilities: they are able to detect signals to which the whole of human society ought to respond. Those of us who are eye-like are able to gather information like scientists, and by using the scientific method. Whatever draws their attention does not necessarily turn the progression of the whole of mankind. But those of us who are ear-like are able to detect the tiniest whispers and subsequently manage to turn to whole of mankind's attention toward it, even when very few actually know what's going on and what we're aiming for.
The eye-like folks are famously familiar to us moderns. We understand their importance and many have developed a kind of superstar status (Curie, Einstein, Hawking) that strongly suggests that the bulk of humankind has no idea what's actually going on. The ear-like folks are those who truly pilot mankind. They are the first to detect signals that the whole of mankind will trail, long before the vast majority of us understand that we're moving, let alone in which direction and for what. The eye-like folks, brilliant as they are and free to look wherever they want, end up looking mostly into the direction in which the ear-like folks point them.
And who, you ask, are those ear-like folks? Well, in the words of Jesus: "He who has ears to hear, let him hear" (Matthew 11:15). The ear-like folks are those who know what the bulk of people want before they realize it. People with this gift are able to produce very helpful items (artistic, theoretical and practical) that will guide the whole of humanity toward a place of collective happiness. People with this gift commonly become very rich, as the whole of society rewards them for their guidance. Still, wealth is no indication of a person's virtue, since many a society has followed their blind guides eagerly into ruin — this theme is overly discussed in stories such as that of the Greek Sirens and the Bible's proverbial Harlot (Proverbs 7:5, Revelation 17:1), whose sensuality made the world's kings and merchants rich (Revelation 18:3).
The Hebrew word for ear is אזן ('ozen). It comes from the verb אזן ('azan), meaning to balance or equalize. Another noun from this same root, or an identical second one, is מאזן (mo'zen), which describes a merchant's scale or balance. From the word for ear comes the denominative verb אזן ('azan), to harken, which emphasizes the turning of one's face to where sound comes from, rather than obedience to some command.
All this points toward the conclusion that man's ears are not primarily organs to hear with but rather organs to build social networks with, and by effect, to build humanity's specific mind with. For more on mankind's mind, read our article on the noun νους (nous), and note the similarity between the words νους (nous), meaning mind, and ους (ous), meaning ear. Also note that our noun ους (ous) is identical to the accusative masculine plural form of the relative pronoun ος (os), and thus means "those". Our noun ους (ous) occurs 37 times, see full concordance, and from it derive:
- Together with the preposition εν (en), meaning in, on, at: the verb ενωτιζομαι (enotizomai), meaning to receive in one's ear, not simply "to hear" but rather to allow to come into one's consideration, or more elaborate: to detect and react to a stimulus that's indetectable to the vast majority of people, but to which the whole of mankind will eventually turn. This highly specialized verb occurs in Acts 2:14 only.
- The noun ωτιον (otion), which is a diminutive form of ους (ous) we mentioned earlier. This diminutive form does not simply describe a little version of the original but rather a constitutional element of some whole. Our noun ωτιον (otion) does not simply mean "little ear" but rather describes the auricle, the visible, external ear. This word is used 5 times, see full concordance, but only in the story of Peter cutting off Malchus' auricle during the arrest of Jesus in the Garden of Gethsemane. This story has puzzled many, but its meaning seems to lie in statecraft. The Bible is concerned about the progression of wisdom, and not at all about politics. That means that Malchus may be a representation of the political sovereign, whose sole purpose in the perspective of the Bible is to serve the high priest. Poor Malchus gets his right ear whacked off by Simon (= Man of Hearing) Peter (= Loose Rock). This obviously immediately throws Malchus' sense of direction off balance (rather than his absolute sense of hearing, which only diminished a bit), and this is clearly a commentary on the international policies of the Herodians, and particularly Agrippa II. Only John lists the names of the key characters of this story, and only Luke reports that Jesus healed the ear. It should be remembered that the gospels are part of a literary tradition that positively dwarfs anything modern, which is why the four gospels have been continuously studied for two millennia. Both Luke and John date from just after the destruction of Jerusalem in 70 CE (and are thus also post-Pauline), and, while ostensibly describing events from the 30s, very obviously also review a much broader window of time.