Being stuck listening to hold music for an extended period is annoying. What’s even more annoying for me is when the IVR system regularly interrupts the hold music with a voice announcement, often telling you something enormously useful like pointing out that you’re on hold. Music I find easy to zone out without paying too much attention to but whenever you get a voice announcement it demands a bit more attention – at least until you’ve worked out that it’s not actually a human yet.
Usually it rings before a human answers, but I don’t know if that’s a standard or anything.
That’s not very common and (unless you’re being connected to a specific person who really does have an option about answering the call) is pretty much a bug. In most normal IVR situations the call oughtn’t to be connected if there’s a possibility it might not be answered.
Seems like a feature to me – an alert that you’re about to be connected to a human.