Out of them, the sound language is common to both human beings and animals. Sign language is also common to human beings and certain types of animals. Only the word language is highly developed among human beings. Certain birds could be trained to pronounce some words while several categories of animals could be trained to understand the word language. Generally, dogs, cats, varieties of birds, fish (sea dogs), horses, cattle belong to this class.
The human being comes out of the mother's womb exercising his vocal chords for the first time and producing sound. He cries for milk. He cries for comfort. He cries for sleep. He cries because of pain and so on. If you observe carefully, you may find that his cry in slightly different forms is conditioned by the requirements of the baby. This cry is musical and gives great delight to the mother. It is able to stir the mother's heart more than any other music in the world.
As the child grows, he expresses his thoughts and feelings through sign language, by expression, smile, laugh, cry, movement of limbs, etc. The child starts communicating through word language after some time. When again the grown up child or the mature human being moves ageing, his moan in sound and jerk (feature of staccato) due to inability or decrease in strength confirms that he is getting nearer to the grave. The second stage of children which is old age is also represented by variation of sound expressions such as groaning or linum and stammer or staccato, etc.
The function of all three forms of language is communication. The sound language originates from instinct or feeling and develops to a fine art of music based on the cultural background of the people of a country. In the development of music as a progression of structures of sounds and rhythm, different terms are used to identify musical sounds of different effect. In common, musical sounds are known as notes. Notes are produced by vocal chords or musical instruments. The sign language originates from instinct on reason and communicated through expression, signs, gestures in which the limbs, cheeks, face, eyes, lips, brows and muscles of the body come into play. This phenomenon of expression through signs has developed into fine arts forms of dance. The word language is mainly based on reason. It is able to communicate definite meanings making use of the palate, tongue, teeth, lips, nose and also grammar, philology and literature verbally and in writing or printing, making use of paper or some sort of base ink, paint or modern methods of printing.
The sign language is the most intelligible and expresses thoughts and feelings directly. The word language is most perfect but artificial and confined to humans only. The sound language which is music expresses feelings and emotions directly and thoughts indirectly. Therefore music is known as the language of emotions or feelings.
