Using Mathf.SmoothDamp() in a foreach loop

Can you use `Mathf.SmoothDamp()` inside a `foreach` loop? As in:

oldSource = GameObject.FindGameObjectWithTag ("backgroundSound").GetComponents<AudioSource> ();

foreach (AudioSource src in oldSource) {
    src.volume = Mathf.SmoothDamp (src.volume, 0, ref currentVelocity, timeToChange);

How would one have to deal with the `ref currentVelocity`, since all those audio sources might be at a different volumes at that time, and change with a different velocity. Obviously, I can't just take the same variable over and over again but how to do that differently?

You can use the variable over and over if you don't care about the results.

In this case, looks like you don't need them, I'd just leave it as you have it.