If you're having trouble hearing the people on your call, or the other person on the line is having trouble hearing you, the first step is to determine if the issue is with the hardware of your phone.
Before you begin, please ensure your volume is turned all the way up in your main Settings app, under Settings > Sounds & Notifications. Then, try these steps:
- Record a short video with the Camera or a voice recording app and play it.
- Go to YouTube and play any video.
Ideally, if you record a video or voice recording, it should play back over the phone's internal speaker or headphones. If you record a video or voice recording and it doesn't play any audio back, but YouTube videos play fine, then there may be a problem with your microphone.
If you record a video and it doesn't play back the audio on the speaker, but it does through the headphones, the problem may be with your speaker.
If both the speaker and microphone work, you can refer to this article for further troubleshooting.
Some phones have two microphones: the primary and the secondary microphone located on the back of the phone. If you're using a case with your phone and it has to microphones, the case may be blocking the microphone, which may account for poor audio when speaking.