The article didn't say, but a soliton is a solution to a nonlinear PDE that keeps its shape while traveling. One real-world example is a tall ocean wave.
A pure, single Gaussian hump is the soliton for homogenous linear media. If you create an audible with the spectral shape of a Gaussian (and therefore also the time shape), it might get quieter as it moves across the room, and longer, but will still "sound" the same.