ABSTRACT
This chapter considers the underlying nature of vibration itself and some of the vocabulary. It also considers the fundamentals of wave theory that underpin the discipline, how vibration is classified when it comes to human response, and how vibration axes are defined. Vibration needs a mechanical structure through which to travel. Complex waves can be produced by the addition of sine waves with different amplitudes, frequencies, and phases. Vibration can be classified using a variety of descriptors. Some of these terms are technical and have specific meaning; others are more generic and the meaning is dependent on the context of use. Human vibration exposures are rarely the simple sine waves. The final classification of human vibration by contact site, effect, and frequency is vibration that causes motion sickness. Human vibration is usually classified as hand-transmitted vibration, whole-body vibration, or motion sickness, and these sub disciplines are often considered separately from one another.
