A call is received but the sound is not heard

Hello Sanka94,

Thank you for reaching out in Apple Support Communities. Are you unable to hear from more than one caller? If so, there are troubleshooting steps that's available that can help resolve this behavior. Here are the steps we encourage for you to follow:

Follow these steps

1. If your device has a Ring/Silent switch, move the switch forwards — towards the device's display —

so that orange isn't showing. On iPad, you can also swipe down from the top right-hand corner to 

open Control Centre and make sure Silent Mode is turned off. 

2. Open Settings > Focus > Do Not Disturb and make sure Do Not Disturb is turned off.

If you want to try more some steps on your own

If you prefer, here are some more steps you can try on your own. After following these steps, you may 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's opening to see if it's blocked or dirty. On iPhone only, make sure the receiver isn't blocked or dirty. 

3. If necessary, clean the speaker or receiver opening with a small, soft-bristled brush. Make sure 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 can't hear any sound, or if your speaker button on the Ringer and

Alerts slider is dimmed, your speaker may need to be serviced.

5. If you can 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 anything, or you hear static or crackling, then your

network or reception could be the issue. Try calling again later or from a different location.

FaceTime isn't available in all countries or regions.

These steps are outlined in this article and can help: If you can't hear any sound or hear distorted sound coming from your iPhone, iPad or iPod touch speaker

Kind regards.