Confirm whether the earbud speaker is blocked. If there is a blockage, please try to use a Q-tip with a bit of rubbing alcohol or a small, clean brush to gently clean it.
2. If you are only using one earbud, ensure that the other earbud is in the charging case.
3. Ensure that you are wearing the earbuds in the correct position. If the earbuds are not worn properly on your ears, you may not achieve the correct call performance.
4. Ensure that the audio output device selected is \"soundcore AeroFit\" and turn up the volume on your device.
5. If you make a call through an app, try using your phone to make a call instead to see if the problem persists.
6. Try testing your earbuds with a different Bluetooth device in a different environment to see if there is any difference.