Symptoms
- Callers say they can't hear you at all
- Voice sounds muffled or cuts in and out
- Mic works fine for voice memos but not calls
- Problem happens with one specific app only
Likely causes
- CommonCase or screen protector covering the microphone holeA thick case can partially or fully block the bottom mic opening.
- CommonLint or debris in the microphone portPocket lint commonly clogs the small mic openings near the charging port.
- PossibleMicrophone permission disabled for the calling appiOS lets you block mic access per app, which silences that app's calls.
- PossibleBluetooth device with its own faulty mic connectedIf a paired headset is active, its mic is used instead of the phone's.
- Less commonInternal microphone hardware failurePhysical damage or liquid exposure can damage the mic component itself.
What to do
- Remove any case and check that nothing is covering the small microphone holes near the charging port and camera.
- Inspect the mic openings with a flashlight for lint and clear gently with a dry, soft-bristled brush.
- Disconnect any Bluetooth headset or car audio so the call uses the phone's built-in mic.
- Go to Settings, find the calling app, and confirm Microphone access is turned on.
- Record a voice memo to test if the mic works outside of calls, which narrows the issue to the call app or Bluetooth.
- Restart the iPhone to clear any stuck audio session.
- Test calls in both a regular call and an app like FaceTime to see if the issue is app-specific.
- If the mic fails in every app and after cleaning, consider a professional repair check.
Tools and parts
- Soft-bristled brush
- Flashlight
Replacement microphone moduleSearch: “iphone microphone replacement”
When to call a pro
If the mic fails across all apps after cleaning and permission checks, a repair shop can test the internal mic hardware.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.