Who were the first people to think of putting sounds into paper and when?

The first known people to attempt to write down sounds were the ancient Sumerians, who lived in Mesopotamia (modern-day Iraq) around 3500 BC. The Sumerians developed a system of writing called cuneiform, which used wedge-shaped marks on clay tablets. Some of these cuneiform tablets contain phonetic symbols, which represent sounds rather than objects or ideas. For example, the Sumerian cuneiform symbol for the sound "ba" was a picture of a mouth.

Other ancient civilizations that developed systems of writing that included phonetic symbols include the Egyptians, the Chinese, and the Mayans. The oldest surviving examples of Egyptian hieroglyphics date back to around 3100 BC, while the oldest surviving examples of Chinese writing date back to around 1500 BC. The Mayans developed a system of writing around 300 AD that included phonetic symbols, as well as logograms (symbols that represent words or ideas) and syllabograms (symbols that represent syllables).

The first alphabets, which are writing systems that use a set of letters to represent individual sounds, were developed in the Middle East around 1500 BC. The earliest known alphabets are the Proto-Sinaitic alphabet and the Ugaritic alphabet. These alphabets were eventually adopted by the Greeks, who developed the Greek alphabet around 800 BC. The Greek alphabet was in turn adopted by the Romans, who developed the Latin alphabet around 600 BC. The Latin alphabet is the ancestor of most of the alphabets used in the world today.