To have a voice is to have an opinion and express yourself in a natural sense, so when this factor is taken away and only your soulmate can truly understand you, then this is called having a paired mind. In this version of the world, the only form of communication is sign language because each one person has an understood language that is different, leaving no understanding to be made. So only you and your unknown soulmate can understand each other's own language. Basically, having a paired mind with someone else is to have those two different and useless languages from before to then be combined and made new for both to communicate in their own space. Of course, there is always an exception in concrete facts. This is little Riley, one who understands all the languages wether it be pair minded, sign, or even the individual languages known to every different person. Also, personal thoughts are heard by Riley, so she can understand everything even something that is unwilling to be understood.