iPhone 12 can’t speak on phone calls

I had the same exact problem!! I called Apple and they set me up with an appointment at Mac solutions plus. Turns out my glass screen protector was on wrong and the cutout part was at the bottom not the top where it should be! 🤦🏼‍♀️🤦🏼‍♀️ I can hear perfectly now that it is on correctly. I would recommend double checking that!

Hmm that is odd.

As you say the microphone for calls is the same used for voice memo.

If the microphones on your iPhone aren't working - Apple Support

I would recomend to try a clean install of your device after a factory reset:

First make sure you have a backup

How to back up your iPhone, iPad, and iPod touch - Apple Support

Then factory reset your device:

Restore your iPhone, iPad, or iPod to factory settings - Apple Support

And set it up without a backup. See if the issue persists.

If it still does not work it is a ponts to a hardware issue and might need service:

Contact Apple for support and service - Apple Support

If that solved it there was a software issue. Try restoring the backup and see if it still works.

if that made the problem come back the backup is the problem

Good luck!

Just sharing has this issue since Dec 2020 on both my 12 pros.

turning off 5G (using 4G) seemed to work for me.

it seemed like a carrier thing if their 5G is too congested or not (just my guess) as similar thing happened to when AT &T years ago when they started selling iPhone.

I was having this problem intermittently with my new iPhone 12 and tried everything I could do myself - reset network settings, reset all settings, and the full factory reset. Nothing worked and after the full factory reset, the problem actually became more prevalent. It was only ever a problem with calls, never an issue recording video with audio or voice memos. I finally called Apple support and they were able to run some software diagnostics over the phone but could not detect the issue. They helped me set up an appointment at my local Apple store where they ran additional diagnostics, got a notice of an error, and was therefore able to give me a replacement phone.

I was having this problem intermittently with my new iPhone 12 and tried everything I could do myself - reset network settings, reset all settings, and the full factory reset. Nothing worked and after the full factory reset, the problem actually became more prevalent. It was only ever a problem with calls, never an issue recording video with audio or voice memos. I finally called Apple support and they were able to run some software diagnostics over the phone but could not detect the issue. They helped me set up an appointment at my local Apple store where they ran additional diagnostics, got a notice of an error, and was therefore able to give me a replacement phone.

I have fix this on my phone! I was having the exact same problem with my iPhone 12. I live in a rural area and none of the local towers support 5G. I cannot make a phone call without it resulting in a dropped call. I could hear the other person saying “hello? Hello?“ Then the car would drop. I assumed that the call was dropping and I was no longer able to send my voice, and I was still able to receive their’s for a few seconds.

To fix this on my phone, I went to Settings, Cellular, Cellular data options, Voice and data. Then selected LTE. I previously had to sit to 5G auto.

I have been working from home and I rely on my phone for everything. After switching to LTE, I have not had a dropped call or audio problem in the past four days.

this appears to be a 5G / iPhone issue. A temp work around until apple fixes is to turn off 5G - Settings/Cellular/Cellular Data Options/Voice & Data - check LTE. This seems to be working

I had this problem on my new 12 too. I reset to factory settings and now I'm not getting anyone telling me they can't hear me. I also had to keep placing my phone on the pad to charge it as it wouldn't connect. That doesn't happen now either. The volume buttons used to race up and down too but that has stopped. Thought it was phone provider but now all working. Definitely software

Today I talked with Apple support they told me to switch the phone 3G instead of 4G. I had no problem with audio on 3G connection.

They told me that it seems ilke a software issue. They told me to reset the phone to factory settings via iTunes and dont use backup.

I couldnt try it yet if anyone tried to reset the phone to factory setting via iTunes please share your opinions about it.

Since resetting my phone to factory settings a few days ago I'm hoping it will stay consistent. So far I can hear all calls and they can hear me

Update: It has now been 10 days since resetting my phone to factory settings. I've had no problems since.

I reset my phone to factory settings snd I did use an earlier back up. I've not had any problems since.

It’s not exactly data, but more precisely 5G.

if you turn off 5G and go with 4G only, you should be fine.

for some reason, the morons at Apple made the 5G band crappy when use with voice calls.

This is the article:

Apple to Fix iPhone 12 ‘No Sound During Calls’ Issue for Free

Mine was an constant issue, no matter who called me it did not work at all.

i just had to bring my phone into apple to get it replaced with a new one. But it could be software in your case I recommend going to an apple store to get it looked at.