Isn’t a vocal vote - “ayes” and “nays” just ripe for abuse in many ways?
There is no accountability to prevent the person presiding over the voice vote from simply selecting the outcome that he or she always wanted to begin with. (By voice vote I don’t mean individually counting “ayes” and “nays” but rather simply having people roar “Yes!” to a proposed measure and then “No” if they oppose it - essentially, measuring which voice is louder.)
First of all, everyone has different decibel power to their voice.
Second, again - what prevents the presiding chairman or whoever from simply selecting the “yes” or “no” outcome that he or she always wanted - even if it was noticeably quieter and had fewer voices - as the winner? There’s no accountability and no recourse, no recounts, etc. It can essentially be a farce.
Voice votes should be used sparingly, but of course if you’re trying to have an only ostensibly democratic institution, then they’re going to get used a lot. And the intention is to demonstrate to outsiders & dissidents that the ‘leadership’ are really in control, so the outsiders and dissidents leave the party, club, or whatever.
That’s how the first night of the GOP convention started. Called for “ayes”, called for “nays”, declared that in the opinion of the Chair, the "ayes’ had it, gaveled and left the stage, all in about 15 seconds.
Voice votes are convenient and save time where the outcome of the vote is inevitable.
In parliamentary systems, the speaker conducts a voice vote and then says “I think the ayes [or noes] have it”. There follows a pause, during which any member of the assembly can demand a division and, if any member does, a division must be held and votes will be tallied.
If, during the pause, nobody calls for a division, the speaker then declares that “the ayes [or noes] have it”, and that is binding.
I’ve no idea how these things work in the Republican party convention. It’s a large assembly, and it’s a safe bet that it contains more than its fair share of bloody-minded and obstructionist people, so a system under which any one member could demand a division on any question might be unworkable. On the other hand, a system under which the presiding officer has unfettered discretion to decree the outcome of voice votes, without challenge, would indeed be open to abuse. You’d like to think that the Convention rules would try to steer some kind of middle course here. But whether they do or not, or whether what happened in the instance cited in the OP was a reasonable implementation of the rules, I have no idea.
Voice votes can indeed be hard to judge. In particular, there is a tendency for those who vote second to answer much louder than those who went first. So even the Chair may be unsure. But a counted division does take quite a bit of time.
Thus when I was trained to Chair Conventions, we often used something else in between: a ‘standing count’. Either some delegate calls for “Division” or the chair just announces that “the chair is in doubt”. Then the chair says “All those in favor of the motion please stand” (or raise your hand, or hold up your delegate badge) and the chair looks around at the number standing, and then says “Please be seated. Now all those opposed the motion please stand”. The chair then looks around again. It’s often quite obvious from that which side has more votes. (Surprising how the volume sounded about equal on the voice vote, but standing clearly shows that it’s 3 or 4 times as many for one side.) Then the chair announces " The Ayes (or Nays) have it, and the motion is passed (or defeated).
Sometimes the vote is still not clear, and then they will have to proceed to an actual counted vote. But mostly that ends it, because everybody in the room could see the results.
If some delegate persists in calling for a counted division, even when the result was clear, then they are really just trying to delay things for some purpose. The chair can try to persuade them, but if they insist, the convention will have to take the time to hold a counted vote. (Sometimes Conventions have included a rule to prevent this, requiring a certain percent of the delegates instead of just one delegate to ask for a counted vote. Typical languages is “All decisions shall be by voice vote, unless x% of registered delegates request otherwise.”)
Under the 2014 Republican Party rules, it takes a majority of delegates of seven states to have a voice vote retaken electronically, and 15 states to have a full state-by-state roll call.
There’s nothing new about “questionable accounting” when it comes to roll call votes; at the 1980 Democratic Convention, four votes to decide the platform were supposed to be roll call votes, but were turned into voice votes that all happened to be in Ted Kennedy’s favor, even though at least one of them sounded to most people like Carter’s side won. IIRC, ABC’s commentator at the time noted that something that was supposed to take around four hours ended up taking less than four minutes.