I have major issues with the call quality on my OnePlus 7 straight out of the box on the hands free mode but it’s ok in the normal telephone mode.
It appears that the microphone has an intermittent problem or poor quality of speech problem in the hands free mode, especially in a motor vehicle.
The fault is within the transmitter or the microphone or the VOX (voice on transmitter) section of the phone. The person who is receiving my calls complains that the volume goes up or down or it fades in & out and or words or parts of words are lost during the conversation (like a faulty VOX circuit). They say that it kind of sounds like I am calling from a bad mobile reception area where parts of your conversation gets chopped (which,
of course I’m not).
If I take the phone off hands free and hold the phone to my face (which you cannot do while driving in Australia because it’s illegal), the phone operates correctly & the receiving party is happy with the quality of the conversation, everything is good. If I connect the phone via an external Bluetooth hands free kit the receiving caller again says that the problem is fixed and the “call is as clear as a bell”. From my end I am not aware of any of these problems because the call is perfect in my direction & of very good sound quality.
I have also done several hard factory resets, removed all apps off the phone, a hard factory reset & then tested the phone with nothing on it ant the fault still remains no matter what I try.
Phone has since been sent back to vendor for refund or replacement they say that there is no fault.
I’ve written to OnePlus and they refuse to get involved in any way shape or form “not their problem”.