PhoneScoop's Specs say this phone has a Half Duplex Speakerphone. Thier definition of implys that only one person can speak at a time like a Walkie Talkie. I find this hard to believe that all Newer Cell Phone would not have FULL Duplex Speakerphones
True full-duplex speakerphones are somewhat rare in cell phones. It requires relatively sophisticated sound processing to prevent feedback. Most speakerphones in cell phones are half-duplex, but most do a good enough job detecting who's speaking - and switching quickly - that you wouldn't notice. Really, most people would be surprised to learn that their phone's speakerphone is technically half-duplex.
It's only if you have a group of people gathered around a phone using it to have a conference call meeting that you really need full-duplex. Most people don't do that with their phones.