I cannot seem to hear any of my friends or anybody online on my xbox. I can still seem to hear the game just cannot here any one. My friends can hear me but i cant hear them....

I have the same problem it has happened before and it then worked just fine after, but now no matter what i tried such as re installing the headset i can not hear anybody in my xbox live party or myself, I tried recording a voice message to try and hear myself but nothing. I can however hear the game and can talk. I just can't hear any myself or anybody talking to me.

If you actually purchased only the ODST game you will not be able to play anybody in Halo 3 online. You will still actually need the Halo 3 disc to play multiplayer online.

Have you checked to see if they are muted?

The regular headsets are very temperamental mate, if you play online alot then would advise getting a turtle beach headset they're awesome

check your NAT settings and make sure they are open. If secured, you'll have problems connecting to anybody.

You may have family settings on xbox 360 that stops you or the same on ps3, check that out

Do the following

• Try new wires (borrow it from friends or neighbour, no need to purchase).
• If you have some other TV at your place or some friend's place you may try connecting this xbox 360 to that TV and check if the TV / monitor is compatible and to see whether the fault is with the TV or console.

However, I would suggest you to go through the following link, as it explains complete procedure to narrow down and troubleshoot the issue with pictures in it.
Do not open the console, as it could void your warranty.
http://support.xbox.com/support/en/us/xbox360/kb.aspx?ID=916158&lcid=1033&category=hardware

Further here is a link to customer care department of xbox 360
United States customers - Online console repair
Outside the United States - Online console repair
Note: Online console repair service is currently not available in all countries and regions.

And for customer support.
Phone numbers

• Toll free: (800) 4MY-XBOX or (800) 469-9269
• Direct dial: (425) 635-7180
• Hearing impaired (TDD device): (866) 740-9269 or (425) 635-7102

Hours of operationPhone assistance is available seven days a week.

• 9:00 A.M. to 1:00 A.M. Eastern Time
• 6:00 A.M. to 10:00 P.M. Pacific Time

For information about how to contact Xbox Support directly, please visit the following Web site:
http://www.xbox.com/support/contact

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Here's my best idea. Join a party on Xbox LIVE with a friend. This will let you communicate outside of Halo 3. If they can't hear you when you're in the party together, then it's your headset.

To have a friend join a party, go to your friends menu and select a friend. It will then give you the option to invite them into your party. Good luck!

xbox live has recently added three ports for wireless internet.
if you know how to open ports (protocols) on your wireless router, then the following should be open (enabled) for your xbox 360s IP adress:
TCP
: 80

TCP and UDP:
:3074
:88
:53

What type of output cable do you have? The older models (before HDMI) had a switch between composite and component output (this is on the output cable itself). If yours has this try switching over and plug in using another method. If this works i'd try a friends cable and see if that fixes your problem.