The "voice vote" is a function of congress that allows the chair to put forth a motion and ask for all in favor and all opposed and then simply pass or halt the motion based on who happens to be in attendance at the time.
Something like this can easily be abused to circumvent opposition to a particular bill by simply holding a vote at an inconvenient time.
The voice vote is an excellent tool to pass routine bills that would normally have no opposition and should be preserved as an overall tool.
However, in it's current state, there are no records of what representatives vote which way on actions or even are present. Please have the regulations updated to require some sort of minimum attendance, or at the very least, record what representatives were present and which way they voted.