Network error

If the issue occurs with all contacts, check whether the device signal is normal. If not (for example, the number of signal bars is small or an "×" is displayed on the signal bars), the call quality will be affected. It is recommended that you switch to another network or move to a place with a good signal and try again.

Volume counterbalance adjustment exception

Go to Settings > Accessibility Features > Accessibility > Audio to check whether Balance is adjusted to the left or right audio channel. If so, slide the Balance bar to the middle and try again.

Observe the receiver position of your phone

The receiver holes are highlighted in red in the following figures. Ensure the phone is positioned with these holes facing your ear. Moving the phone close to your ear during a call may block the receiver, causing volume fluctuations or noises.

Whether the phone does not come with a receiver

If your phone does not come with a receiver, such as P30 Pro, Mate 30 Pro, or the P40 series, it indicates that your phone outputs audio through the screen. In this case, place your ear against the screen during a call. Otherwise, the voice volume may be low or unstable, as shown in the figure below.

Incompatibility with third-party software

If the issue occurs only when you are using third-party software to make calls, it is recommended that you reinstall the third-party software or update your phone/tablet system version.

Hardware fault

If this issue only occurs during calls with a specific person, their device may be faulty. Check whether their microphone is blocked by their finger, protective case, or other foreign objects. If you have made multiple calls but no issues occur after you switch to Speaker mode or use a headset, the receiver may be blocked or the receiver hardware may be faulty. Check whether the receiver hole is blocked by a protective film or other foreign objects. If so, remove the screen protector or foreign objects with a soft brush, and try again.

If the issue persists, it may be caused by other hardware faults. In this case, contact Huawei customer service hotline. Alternatively, back up your data and take your device and proof of purchase to a nearby Huawei Customer Service Center for assistance.