The running sound do not bother me (and I think its weird without it), neither I think its too loud.
But from listening it, it sounds to be playing on the wrong frames.
If my retired musician ears isn't playing with me, your sounds triggers like:
(X means sound, - means pause)
X--X----
SOUND, pause, pause, SOUND, pause, pause, pause, pause
(it´s easy to get because if you listen carefullly, the 2 sounds have a short pause between then, but a long pause after the second one)
Since your run animation looks to have 8 frames, the sound should be evenly split (right now, you have a sound, 2 pauses, a sound again then 4 pauses), like this:
X---X---
SOUND, pause, pause, pause, SOUND, pause, pause, pause.
IOW, split the sound and pause evenly
Some extra tips:
- Avoid using the step sound on the first frame of the Run animation, because if the play do a short run and then walk, he will listen the step sound too often
- You can use different levels for each leg (some games, like KOF and other SNK games have a different step sound for each leg)