Patanjali's yoga sutras

श्रोत्राकाशयोः संबन्धसंयमाद्दिव्यं श्रोत्रम्
śrotra-ākāśayoḥ saṁbandha-saṁyamāt divyaṁ śrotram

śrotra श्रोत्रा – ear; hearing
ākāśayoḥ काशयो – ether, one of the five elements
saṁbandha संबन्ध – relationship
saṁyamāt संयमा – mediate on
divyaṁ द्दिव्यं – superhuman
śrotram श्रोत्रम् – ear/hearing; sacred knowledge

Each of the elements is linked with one of the five senses: hearing and ether; touch and air; sight and fire; taste and water; and smell and earth.

The element of ether has its seat at the third eye and is represented by a spiral, which also happens to be the shape of the cochlea of the inner ear.

Ether is the medium through which sound travels. Sound can’t be heard in empty space. Sound waves need to move through particles of matter (gasses, liquids, or solids) to vibrate and transmit energy.

These connections appear to describe the universe, but they may just draw a line around our limited experience of it.

In his commentary on the Katha Upanishad, Swami Vivekananda says:

We can see, we can hear, we can touch, we can smell, and we can taste. We cannot do anything more than this in this world. We see a fivefold manifestation of the universe—earth, water, fire, air and ether—because of the organs which are fivefold. Some wise men have held that if we had millions of sense organs, we would behold the world in a million ways, and not only in the limited way as it appears to the fivefold senses.