Why can't anyone hear me when I'm talking on speaker phone and their talking at the same time? It's like the phone won't relay my voice while their speaking....

I've recently upgraded to Tmobiles most recent OS. Thought it was fixed, same issue.

It's because the speakerphone is only a half-duplex speakerphone, as opposed to a full-duplex one.

Half-duplex speakerphones only allow sound to travel in one direction at a time. So, the users have to remain quiet while the other is speaking.

Full-duplex speakerphones can transmit and receive sounds simultaneously.

--Ariel