Could anyone give me some feedback about wether they feel investing in a pair of headphones would be benificial. Are the Koss that come with the machine good enough or would a different set be better. The only things I don't like about the Koss is it does not keep out extearnal noise and no volume control. Which headphones would be recommended and what are some of the benifits that you like or that help you. THANKS ALOT CHEVY FROM OREGON