1098
Śrīmad-Bhāgavatam
[Canto 3, Ch. 26]
tāmasāt —from egoism in ignorance;  ca —and;  vikurvāṇāt —undergoing transformation;  bhagavat-vīrya —by the energy of the Supreme Personality of Godhead;  coditāt —impelled;  śabda-mātram —the subtle element sound;  abhūt —was manifested;  tasmāt —from that;  nabhaḥ —ether;  śrotram —the sense of hearing;  tu —then;  śabda-gam —which catches sound.
TRANSLATION
When egoism in ignorance is agitated by the sex energy of the Supreme Personality of Godhead, the subtle element sound is manifested, and from sound comes the ethereal sky and the sense of hearing.
PURPORT
It appears from this verse that all the objects of our sense gratification are the products of egoism in ignorance. It is understood from this verse that by agitation of the element of egoism in ignorance the first thing produced was sound, which is the subtle form of ether. It is stated also in the  Vedānta-sūtra  that sound is the origin of all objects of material possession and that by sound one can also dissolve this material existence.  Anāvṛttiḥ śabdāt  means “liberation by sound.” The entire material manifestation began from sound, and sound can also end material entanglement, if it has a particular potency. The particular sound capable of doing this is the transcendental vibration  Hare Kṛṣṇa . Our entanglement in material affairs has begun from material sound. Now we must purify that sound in spiritual understanding. There is sound in the spiritual world also. If we approach that sound, then our spiritual life begins, and the other requirements for spiritual advancement can be supplied. We have to understand very clearly that sound is the beginning of the creation of all material objects for our sense gratification. Similarly, if sound is purified, our spiritual necessities also are produced from sound.
Here it is said that from sound the ether became manifested and that the air became manifested from ether. How the ethereal sky comes from sound, how the air comes from sky and how fire comes from air will be explained later on. Sound is the cause of the sky, and sky is the cause of  śrotram , the ear. The ear is the first sense for receiving knowledge. One must give aural reception to any knowledge one wants to receive, either material or spiritual. Therefore  śrotram  is very important. The Vedic knowledge is called  śruti ; knowledge has to be received by hearing. By hearing only can we have access to either material or spiritual enjoyment.
In the material world, we manufacture many things for our material comfort simply by hearing. They are already there, but just by hearing,