Originally Posted by sitlet
I agree with the above post. If your headphones do have an optical input, and you aren't hearing any sound, perhaps the dvd player is not set to output to the optical port, or is outputting the wrong format.
The only purpose of an optical port on a dvd player would be to output audio (unless it's a recorder also and even then that might not be a two-way street), can't think of any tv's that accept an optical input but it's possible I suppose, would expect it normally to be an audio output also. The signal via optical is not sufficient to drive speakers, it isn't even in the right format as it first needs to be transformed to an analog signal then amplified sufficiently (even the very small speakers in a pair of headphones needs amplification over an analog line level signal.....and a volume control even if they could handle a line level input
). Without knowing what headphones not possible to tell much of anything.