Check for anything that might be covering the microphone
- Ensure that you are not covering the microphone or speaker on the device.
- Ensure the protective film that ships with the device has been removed.
- If you are using a case, cover or screen protector on the device, try removing and trying without it.
The earpiece volume on the device can only be adjusted while on a call.
- The proximity sensor may require you to pull the phone away from the your face in order to adjust the volume.
- Try making a test call and adjust the call volume.
- While in call try using the speakerphone or a wired headset to see if issue persists.
(If issue exists while using other method, problem is likely related to signal strength or coverage area)
- You may experience distorted audio while at the highest setting, try decreasing the volume to see if this corrects the problem.
Try power cycling the device.
It is a good practice to power cycle the device periodically to clear out buffers and memory that may lead to intermittent issues.