So I've been having this weird issue where people keep telling me they can barely hear me during phone calls. I have an iPhone 13 and it started about a week ago. The microphone seems to work fine for voice memos and Siri, but during actual phone calls, people say I sound really distant or muffled. I've tried cleaning the microphone holes with a soft brush, restarting the phone, and even resetting network settings. Nothing seems to help. Has anyone else dealt with smartphone microphone problems like this? Is this a common hardware failure or could it be a software bug?
Smartphone microphone problems like this are actually pretty common on iPhones. There are usually three microphones - one at the bottom, one at the top near the front camera, and one on the back. The one used for phone calls is typically the bottom microphone. Check if there's any lint or debris blocking it. Sometimes pocket lint gets packed in there really tight. Use a soft brush or toothpick VERY gently to clean it out. If that doesn't work, it could be water damage or a failed microphone component.
I had similar smartphone microphone problems with my iPhone 12. Turns out iOS was automatically switching between microphones based on which it thought was best, but it was choosing wrong. Try making calls with speakerphone on - if people can hear you fine then, it's definitely the bottom microphone that's the problem. Also check if voice memos recorded with the rear camera work but ones with the front camera don't - that would confirm which specific microphone is failing.
My friend had smartphone microphone problems after getting his phone wet. The microphone worked for everything except calls because the water damage affected the noise cancellation circuitry. Apple's noise cancellation uses multiple microphones to filter background noise, and if one is damaged, the whole system can fail. If you've had any liquid exposure, that could explain why it works for some things but not calls.
Check if you have any screen protectors or cases that might be covering the microphone holes. I've seen cases where people install thick screen protectors that actually block the top microphone near the front camera. Also, try recording a voice memo while covering different areas of the phone with your finger to isolate which microphone is having smartphone microphone problems.