How do I turn on my headphones?

Yup. If the headphones are driven by the TV, then turning down the TV turns down the headphones. Check to see if the TV has an audio output setting where you can select either the TV speakers or the headphone jack. What brand and model TV is it?

sounds like you are plugged into a speaker jack-not the headphone jack-cheers Denny

Just found this and it worked! Hope it does for you as well:
There should be a button on the DVD remote control with a headphone symbol on it. Make sure the headphones are turned on(red indicator on earpiece) and push the headphone button on remote. The headphones will only work in the back seats of the vehicle. Once you have audio to the headphones, you should be able to hit the AM/FM button on the radio and listen to the radio while back passengers use the headphones for video.

Change your audio settings to headphones :)

Contrary to what's posted above, the Marshall MG series does not pass the speaker power output through the headphone jack, and inserting the headphones into the jack does not disable the speaker. The headphone amp is a separate circuit and it's input is taken before the master volume. So Jan's post is exactly right. Turn off the master volume and turn up all the other gain/volumes as high as they will go. The other issue is that the headphone jack's output does not drive low efficiency headphones well, so you need some headphones similar to Sony's MDR-V700s to hear it well. Earbuds just don't cut it.

You should have all the necessary cables to do this with the package you bought, the wire which has a headphone style plug on each end should be plugged into the headphone jack on your tv.

If they dont work then there are two further things that could be at fault:

A: The headphone audio volume controls and the actual speaker volume controls on tvs are totally different and if the actual headphone volume is turned down then you will get an interference type noise thru your headphones as no sound is being detected by the reciever and therefore they go into kind of a standby mode. !!!!!!!!!!Try looking in your TV settings menu to make sure your headphone volume is turned up!!!!

B: being an owner of a pair of these headphones I know how audio the cable can easily turn faulty from prolonged use us. The wires can easily break inside but look fine from the outside so get a new one. Headphone jack to Headphone jack cable.

I use these along with my xbox 360 wireless earpiece (fits nicely under the headphones) and I think they're far superior to the Turtle beach headphones +++ My setup is 100% wireless which also makes it better than any turtle beach setup on the market.

Ok.. first.. the simple thing is to go into your television menu and turn the television speaker OFF.
Then exit the menu and turn the volume up.. try your headphones now.

Next.. check the back of the TV for a FIXED AUDIO OUT.. plut your headphones into these outputs.. if you have these.. you can simply turn the set down.. and use the volume control on the headphones.

Is there a switch to turn on the headphone port? Is there a control on the headphones to adjust the volume (on a volume level on the side of the laptop)? Also, when the headphones are plugged into the laptop, go into your sound settings and turn up the master volume (and wave volume if it is low.. If that works, make sure to turn it back down when disconnecting the headphones).

Also, do the headphones work in another device (stereo, etc..)?

Look in your TV's menu options. I have an RCA TV which allows me to turn on (or off) the headphone port and set the volume of the headphones. Once you turn the headphone volume up, then you can turn the TV Volume all the way down with your TV remote while the headphone volume remains where you set it. Hope this works for you.