It is not clear whether the voice transmitter works at all, in which it is also necessary to insert the battery or not. I insert the Battery, I speak, it seems to be audible, but if I do not turn off the microphone, for example, I pressed Caps lock twice, then it will still be heard as one of these speakers, even if I take the battery out of there. Even if I run away from there without turning off the microphone, it will still be heard as if it still works. And when, for example, I turn my left ear to the speaker and turn on the microphone, the sound remains that way, if it is static, even if I run far away, I will still hear what I am saying if the speaker is in the position where he was and at the same distance.