1. Make sure the volume is set to maximum on both the earbuds and the connected device.

2. Try using ear tips that fit more snugly and ensure the earbuds are positioned correctly to create a proper seal. An improper fit can affect call quality.

3. Switch to the phone's microphone and make a call to see if the issue persists.

4. Test the earbuds in a quieter environment.

If you encounter any other issues or your issue has not been resolved, please contact us for further assistance.