Here are some suggestions that may help:
- Ensure that the microphone is attached properly and bend it until it is parallel to your mouth.

- Ensure that the microphone diaphragm is in front of your mouth.

- Check the controls and make sure that the microphone is not muted. The green band around the mute button will show when the microphone is not muted.

- Ensure that the microphone level on your console or PC is not set to zero or muted. Checking for troubleshooting guides from your console's manufacturer support site may also help.