But it can also be the result of a number of health conditions, such as: 1  Noise-induced hearing loss. 2  Ear and sinus infections. 3  Diseases of the heart or blood vessels. 4  MÃ©niÃ¨reâs disease. 5  Brain tumors. 6  Hormonal changes in women. 7  Thyroid abnormalities.
The Aryan Migration. Before the time of the Aryan migration into the Indian subcontinent, there was a highly developed civilization in ancient India known as the Indus Valley Civilization, which was located in what is Pakistan and northwest India today, on the fertile flood plain of the Indus River and its vicinity.he Aryan Migration. Before the time of the Aryan migration into the Indian subcontinent, there was a highly developed civilization in ancient India known as the Indus Valley Civilization, which was located in what is Pakistan and northwest India today, on the fertile flood plain of the Indus River and its vicinity.
Smaller civilizations arose in Elam in modern-day Iran, and on the island of Crete in the Aegean Sea, as well as the Olmec civilization and the Caral civilization in modern-day Mexico and Peru. The Mesopotamian civilization of Sumer is officially is believed to have begun around 4000-3500 BC. It ended at 2334 BC with the rise of Akkad, and is the world's first civilization. The Egyptian civilization of the Nile Valley started at around 3200 BC. It ended at around 343 BC, at the start of the Achaemenid dynasty's control of Egypt. This is one of the three oldest civilizations in the world.