What is the sudden silence of Apple's mobile phone 6s?

Turn the switch forward (that is, toward the iPhone display) so that the orange side of the switch is not exposed.

Open Settings > Focus Mode > do not disturb mode, and make sure that do not disturb mode is turned off.

Remove all screen protectors, protective films or protective covers to ensure that the speaker opening and receiver are not blocked or dirty.

Go to settings > sounds (or settings) >; "Sound and Touch"), and then drag the ringtone and reminder sliders back and forth several times.

If you can hear the sound, try to make a call and turn on the speakerphone.

Learn what to do if there is no sound or sound distortion.

For additional assistance, please contact Apple Support.