My iPhone 12 plus is having sound issues for calls, it is muffled and I need to use speaker

If you have a hearing or sound issue on your device then please try some of these processes to set it right

1. If you have a distorted sound issue on your iPhone --> If you hear no sound or distorted sound from your iPhone, iPad
2. If you are not able to hear the other person, click this...>If you can't hear a person on a call or voicemail or if the sound isn't ...
3. If you only hear through speakerphone mode --> If your iPhone is stuck in headphone mode - Apple Support
4. If the other person is not able to listen to you then please click this to identify the issue --> If the microphones on your iPhone, iPad, and iPod touch aren't ...

If the above options do not mitigate the issues then Contact your carrier and then Contact Apple Support

There are several potential reasons for distorted voice calls on an iPhone. Here are some common factors that can contribute to this issue:

1. A weak or unstable cellular network signal can result in voice call distortion. If the signal strength is low, the audio quality may suffer, leading to distortion, dropouts, or static during calls.
2. High network traffic or congestion can affect voice call quality. When there are too many users trying to access the network simultaneously, it can result in degraded call quality or distortion.
3. It's recommended to keep your iPhone's software up to date and regularly check for app updates.
4. If you are using a Bluetooth headset or speakerphone during calls, interference or compatibility issues can lead to distorted audio. Try disconnecting any connected Bluetooth devices and check if the voice quality improves.
5. Voice call distortion can also be attributed to problems on the network provider's end. Temporary network outages, infrastructure issues, or maintenance work can affect call quality in specific areas or during certain times.

If you're experiencing persistent voice call distortion on your iPhone, it's recommended to troubleshoot the problem by following these steps:

1. Check your network signal strength and switch to a different location if possible to see if the issue persists.
2. Restart your iPhone to refresh the software and temporary settings.
3. Disable any Bluetooth devices connected to your iPhone during calls and check if the distortion improves.
4. Verify that your iPhone's software is up to date and install any available updates.
5. Contact your network provider to inquire about any known issues in your area.
6. If the problem persists, consider contacting or visiting an Apple authorized service center to diagnose and address any hardware-related problems.