Man alone, among all the living beings, has had the privilege of being endowed with the power of speech, with which he can convey his thoughts and feelings to others. However he has even been curious to know whether animals, birds and even worms have their own means of communication. Patañjali (200 B. C.) the ancient teacher of Yoga, asserts in his famous work, the Yogasūtras (3.17), that a yogi can acquire that extraordinary power by practising saṁyama (See BHŪTAJAYA for an explanation of this word.) on the three separate aspects of every word.
This can be illustrated with an example. When a person utters the word ‘cow’ we get the knowledge of a cow. However, on analysis, we find that three things are involved in this. The word itself is a sound produced by uttering the three letters c, o and w, in succession by the vocal organs. The animal cow is a solid external object perceptible to the eyes and the hands. The knowledge of it produced in the mind is of the form of mental waves. Ordinarily, these three are mixed up and yet, give us a unitive experience.
If the yogi can manage to separate these three in his mind and practise saṁyama on each of them separately, then, he realizes the basic truths underlying each of them, viz., śabda (sound), artha (object signified) and pratyaya (knowledge in the form of mental waves). This will now empower him to ‘know’ the meaning of all the sounds uttered by all the living beings including those of the animal kingdom.
Purāṇas sometimes mention the names of persons who had acquired this power.