Please follow below steps for troubleshooting:
1. Plug the headset into ASUS phone or tablet.
2. Play music file to test whether the sounds are normal.
3. Record a voice and play it to test whether the microphone is normal.
4. Use other headset to cross check the functions again.
5. If the headset does not function normally in the tests, send the headset to local service center for further assistance.