Mechanical wave: a wave that requires a medium in which to travel  and therefore, cannot propagate in vacuum.

Longitudinal wave: a wave motion parallel to the energy source

Parameters of a wave: cycle, frequency, period, wavelengh, propation speed

Parameters to described pulsed waves: Pulse repetition time  Pulse repetition period Pulse duration Duty factor 
Spatial pulse lengh Amplitude Power Intensity

Acoustic varible:Pressure, temperature, density and particle movement