Vibrations are the oscillating movements of an object or medium caused by a disturbance. There are several synonyms for the word "vibrations" such as tremors, quivers, shudders, shakes, jolts, quakes, throbs, pulses, oscillations, and reverberations. Tremors usually refer to small involuntary shaking movements, while shudders and quivers may imply a sudden, involuntary movement due to fear or cold. Shakes and jolts are often used to describe sudden, jerky movements, while quakes are reserved for seismic activity. Throbs and pulses are often used to describe rhythmic movements, while oscillations refer to repetitive back and forth movements. Lastly, reverberations refer to the echoes or effects of vibrations.