help whit WaitForSecond use.

can someone give me a solution or example?
look at the example of WaitForSecond but get it right!

I have 3 AudioSource:

L
M
H

these are executed automatically with engine revs …
I want to do, is to push a button (next gear) 3 audios stop for the number of seconds to put on a “public float”

eg
if (input.GetbuttonDown (“next”)) {
LSource.Stop ();
MSource.Stop ();
HSource.Stop ();
(for x amount of time)
}

the script is written in c #!

Read this: http://docs.unity3d.com/Manual/Coroutines.html

void Update()
{
    if (input.GetbuttonDown ("next")) 
    {
        StartCoroutine( MyCoroutine() );
    }
}

IEnumerator MyCoroutine()
{
    // Do stuff before wait, ie Stop sounds
    yield return new WaitForSeconds(3f);
    // Do whatever after X seconds, ie Continue playing sounds
}