The primary responsibilities of human resources are: 1  C - Compensation. 2  H - Human resource development. 3  E - Employee and labor relations. 4  S - Safety and health. 5  S - Staff.
A new technique uses sound waves to levitate objects and move them in mid-air. Credit: Dimos Poulikakos View full size image. View full size image. Hold on to your wand, Harry Potter: Science has outdone even your best Leviosa! levitation spell.
Once in your ear, those sound waves cause your ear drum to vibrate. This sends signals to your brain that you heard a sound. Sound waves can be represented as a wavy line. Music and sounds associated with music such as bells and birds chirping create regular sound wave patterns such as this. Noises such as doors closing, traffic, or blenders make erratic wave patterns like this. The real difference between noises and music is in the patterns of their sounds waves. We tend to find regular, orderly sound waves much more appealing and label them as musical sounds. Sound waves can move through solids, liquids, and gases. Sometimes, itâs hard to image sound as something that can move.