How would you describe the sound of this plainly audible jitter?
In my system, the reduction of jitter resulted in three audible improvements: Increased perceived resolution, improved imaging focus, and the removal of high frequency harshness. So, to answer your question, the sound of jitter in my system was decreased perceived resolution, diminished imaging focus, and the presence of high frequency harshness.
If you are wondering how I know that these improvements were attributable to the reduction of jitter...they resulted from the addition of an Empirical Audio reclocker - its raison d'etre is the reduction of jitter.
Bryon