I would think it would (become a crutch) IF you used it so much as to become 'conditioned' by said use. Any meditation tape, or goodly music, fresh cool air etc could also become a crutch however...
However again all development taken separately would be of keen benefit.
Keeping primary skills separated is advantageous. But I would think using a holosync meditation tape could increase the clarity of impact. I will try it again, with a big dictionary. <smiles>
I think that if you are already skilled in concentration, meditation etc, then any circumstance will do. At least that is what I have found so far.
