"... Al Birūni had it in his astrological charts as Amphora, a Two-handled Wine-jar, that he may have adopted from Ausonius the poet of our 4th century. Even Vercingetorix, Caesar’s foe in Gaul, 52 B.C., is said to have put the similar figure on his stateres with the title Diota, a Two-eared Jar."

I think a pair of ear holes may have been a sign for Aquarius (or Saturn), because such are located between the front side (the face) of the head and its backside. Thus they can illustrate the holes through which Sun arrives in the morning and leaves in the evening:

Ogotemmêli touched upon the subject (cfr at Toki) - and his little 8th drum probably corresponds to Saturn (because the creator of a new fire will tend to be inseparable from the little one) - when he was describing the origin of the armpit drum:

... The most important of all drums, he said, was the armpit drum. The Nummo made it. It consists of two hemispherical wooden cups connected through their centres by a slender cylinder. It is like an hour-glass with a very long narrow neck. With this instrument tucked between his left arm and armpit, the drummer, by pressing on the hollow structure of thin wood, can tighten or relax the tension on the skins and so modify the tone.

'The Nummo made it. He made a picture of it with his fingers, as children do today in games with string.' Holding his hands apart, he passed a thread ten times round each of the four fingers, but not the thumb. He thus had forty loops on each hand, making eighty threads in all, which, he pointed out, was also the number of teeth of his jaws. The palms of his hands represented the skins of the drum, and thus to play on the drum was, symbolically, to play on the hands of the Nummo.

But what do they represent? Cupping his two hands behind his ears, Ogotemmêli explained that the spirit had no external ears but only auditory holes. 'His hands serve for ears,' he said; 'to enable him to hear he always holds them on each side of his head. To tap the drum is to tap the Nummo's palms, to tap, that is, his ears.'

Holding before him the web of threads which represented a weft, the Spirit with his tongue interlaced them with a kind of endless chain made of a thin strip of copper. He coiled this in a spiral of eighty turns, and throughout the process he spoke as he had done when teaching the art of weaving. But what he said was new. It was the third Word, which he was revealing to men ...

The armpit generates power:

... Constantly hunting about she at last found a snail. To endow it with power she placed it under her arm, lay down and slept for three days. Then she let it free, and still hunting about she found another snail bigger than the first one, and treated it in the same way ...

The form of the armpit drum is basically that of Mount Meru, the world mountain:

(The picture is copied from Hamlet’s Mill)