simple harmonic quantity

2.19  simple harmonic quantity. Quantity that is a sinusoidal function of the independent...

periodic quantity

2.09  periodic quantity. Oscillating quantity whose values identically recur at equal increments of the independent variable.

nonlinear acoustics

2.83  nonlinear acoustics. Science of sound in which the amplitude of particle displacement is sufficiently large that linear approximations to the properties of the medium and/or the equations of motion are no longer sufficient and consequently higher order...