Can someone please explain why I may have a problem understanding my daughter on the phone.

So this is the issue. I kept thinking the problem was maybe me. I don’t understand my daughters speech on the phone. I thought it was just me, but my sister says she has the same problem understanding my daughter on the phone.

I thought it was the phone or the carrier for her was crap. But it doesn’t matter who’s phone she uses. It’s only her. I understand her husband just fine on her phone.

In person I understand her very well. Just not on the phone. Even if she speaks up, I have a problem. She sounds like she is trying to speak with her hand over the speaker. I know she speaks loud because I’ve seen her talk on the phone plenty of times and I can hear her clearly from half a room away.

A good portion of her lively hood is conducted on the phone and my husband says he understands her fine, but I have a difficult time. But myself and my siblings have a hard time understanding her on the phone.

Is she speaking to closely to the microphone, or cupping her hand on the phone, or is there a hereditary problem with my siblings and I that keep us from understanding her on the phone?