iPhone 13 caller sounds robotic

Hello CShakespeare,

Welcome to Apple Support Communities!

We want to make sure the sound works perfectly so you can hear the caller via your iPhone.

Try these steps when the speaker doesn't sound as it should:

"If you want to try more steps on your own

If you prefer, here are some more steps you can try on your own. After following these steps, you might still need to contact Apple Support to discuss service options.

1. Remove all screen protectors, films, or cases from your device. 
2. Check the speaker opening to see if it's blocked or dirty. On iPhone only, make sure that the receiver isn't blocked or dirty. 
3. If necessary, clean the speaker or receiver opening with a small, soft-bristled brush. Make sure that the brush is clean and dry.
4. Go to Settings > Sounds (or Settings > Sounds & Haptics), and drag the Ringer and Alerts slider back and forth a few times. If you don't hear any sound, or if your speaker button on the Ringer and Alerts slider is dimmed, your speaker might need service.
5. If you hear sound, try making a call with your iPhone and turn on speakerphone. On iPad or iPod touch, make a FaceTime call. If you still can't hear, or hear static or crackling, then your network or reception could be the issue. Try to call again later, or from a different location."

This Apple Support page has the full details: If you hear no sound or distorted sound from your iPhone, iPad, or iPod touch speaker - Apple Support

To further isolate the issue, test to see if this only happens on calls or when using other apps like Voice Memos.

We hope this helps to get the sound working normally again.

Cheers!

Usually when this happens, it is due to a weak cellular signal. If you are near a WiFi signal, try switching to WiFi calling and see if that helps.

This can also happen if you are using a bluetooth device on your call and you are at a distance from your phone or the signal is being blocked by an obstacle between your headset and the phone.