Can I ask why you would want that?  Its behaving properly not scrubbing the audio when moving forward and backward one frame.  I am curious though why you are wanting that, perhaps there's a solution to the main issue your having.

I don't believe that is an option, I could be wrong.  There are programs that allow you to do that though, I believe.  Flipbook might be one.  I haven't used that in a while.  What rig are you using?  What machine specs, can you hide things temporarily to quickly just scrub through the scene?  It may not be ideal, but I think it's the only way you can do that if you're rig is slowing maya down.