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 actually an energy wave of molecules that create a vibration. Sound can travel through and bend around many objects, including water. Check out how sound works: 1  When an object moves it creates a vibration. 2  Vibrations move air particles around. 3  These moving particles are constantly bumping into each other. 4  Our ears can pick up these particle-vibrations as sound. 5  Fast moving particles create a high sound, while slow ones are low-sounding.