If you are experiencing poor call quality on your mobile device:

1. Check your cellular network – poor coverage or interference in one area could lead to poor call quality.
2. Restart your device – this will often flush out any bugs and may improve the call experience.
3. Check your settings – make sure the correct microphone and sound settings are selected for best performance.
4. Check your phone's hardware – a faulty microphone or faulty software can lead to poor call quality.