Major players in the drama of 19th-century Texas were definitely the Comanches who at this time swept down from the cool highlands of the southern Rockies, and, mounted on horses, drove other tribes from West Texas.
What is SOUND? The periodic mechanical vibrations and waves in gases, liquids and solid elastic media. Specifically the sensation felt when the eardrum is acted upon by air vibrations within a limited frequency range, ie 20 Hz to 20 kHz. Sound of a frequency below 20 Hz is called infra. STRUCTURE-BORNE SOUND.
Sound is a kind of energy created when something vibrates. When this vibration reaches an ear, it is translated into what we recognize as a sound. Sound vibration must travel through matter. This is typically air. When you say, Hello, to a friend, the air parts (called molecules) vibrate in small waves which travel to the friend and they hear the word Hello.. Sound can also travel through other matter. Tap on the table.