I can confirm this is an issue with iPhone X which I just discovered on my first conference call with it. I do conference calls several times a week and never had this problem with the iPhone 6s this X replaced.
My use case: on the 6s I would plug in earbuds and use the phone's built in mics to do the call. It worked awesome! Tried the same with the IPhone X using a headphone/charge port adapter, same earbuds. I have a quiet office environment from where I make the calls.
My symptoms with the iPhone X:
- with earbuds plugged in, people complain they can hardly hear me.
- As soon as I unplug the earbuds and use the "speaker" function (from the call screen), everyone says they can hear me normally
Based on the change in audibility transitioning from 1-->2 above, it can't be a hardware issue such as a case. It is either:
- there are multiple mics, but some get turned off when earbuds are in for some reason (bug)
- as others point out, there maybe something wrong with the noise cancellation which for some reason doesn't happen when in speakerphone mode, but happens when earbuds are plugged in (bug)
This is an impactful problem for me. I use the iphone for business and using earbuds for conference calls lets me hear everything much better than through the speaker, especially with offshore conference calls. If it doesn't get corrected, I need to look at a droid phone if I can exchange or definitely on the next go around. If I keep it, it sounds like I may need to invest in some external hardware because of Apple's software problem. It's disappointing Apple is dismissing this as a case problem. Quality and customer service are falling off ever so slightly year over year.