Is this xbox one?
If you can't hear sound, or if others can't hear you when you use the Xbox One Chat Headset, try the following solutions first:
Disconnect the headset or unplug the headset cable from the bottom of the controller, and then reconnect it firmly to the controller (in the expansion port for a headset or the 3.5-mm port for a 3.5-mm chat headset).
Note If you have a 3.5-mm chat headset, never pull on the headset cable when removing it from your controller. Remove your headset from your controller by pulling on the body of the headset plug.
Make sure the headset is not muted. To do this, check the mute button on the headset controls. (For a headset, the mute button is on the left side of the connector that is plugged into the expansion port of the controller. For a 3.5-mm chat headset, the mute button is a slider button on the front of the audio controls that are in the middle of the headset cable.)
Increase the audio. If you're using a headset plugged into the 3.5-mm port, go to Settings, choose Devices & accessories, and then select your controller and adjust your audio options.
Try using a different controller or headset to check for a hardware malfunction.