This model doesn't have a headphone jack. The only JVC TV in the series that does is the model AV-20D202. For the JVC AV-2732, use the RCA audio out jacks with an RCA to 3.5 mm adapter to connect to the headphones. The front audio jacks are audio in (for the audio from a video camera for example).
When you use any external speakers or headphones through the audio out jacks, make sure to turn off the TV speakers. Press Menu and navigate down to TV Speakers (up/down arrows). Then use the right/left arrows to select Off and then Exit the menu. Make sure you scroll the TV volume before doing this. Note: if your headphones do not have a volume control they are a bad choice for this type of audio output.
You can find the manual for the TV here: http://books.jvc.com/booklist.asp?Model=AV-27230
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