To improve the phone call quality, try the following suggestions:

• Verify the mobile phone signal strength and/or move to a location with stronger reception
• Adjust the position of the phone, making sure there are no obstacles between the phone and the hearing aids such as your body, a wall, or hard surface as these can interfere with the wireless audio signal
• Make sure the maximum distance between the phone and the hearing aids is not exceeded. Although the official Bluetooth standard indicates 10 m / 30 ft as the maximum range, the real range depends on many factors and may be shorter
•  When relocating during a call, make sure to take the phone along
• Make sure that the phone is streaming the call through the hearing aids and not the speaker of the phone. For this, set the phone call audio routing to Bluetooth headset and not to the phone speaker.