The system would enable people to register or check in on a voice authentication system, without their actual voice ever leaving their smartphone. This reduces the risk that a fraudster will obtain the person's voice biometric data, which could subsequently be used to access bank, health care or other personal accounts.
Preventing the transmission of voice data from client to server doesn't seem to be the major problem with voiceprint authentication to me, since in every spy movie they just record the person while they're talking...