In a compressible sound transmission medium - mainly air - air particles get an accelerated motion: the particle acceleration or sound acceleration with the symbol a in $m/s2$. In acoustics or physics, acceleration (symbol: $a$) is defined as the rate of change (or time derivative) of velocity.
$a = \frac{\partial v}{\partial t}$, where $v$ is sound particle velocity and $t$ is time.
Applicable units are those of quantitykind:Acceleration
Applicable units are those of quantitykind:LinearAcceleration
Sound Particle Acceleration