I put my fingers in my ears and sing La La La La to keep from getting information I do not want to know. Or, I just hold out my hand and repeatedly say stop it, stop it, stop it, in hopes of drowning out sounds. I use these tactics when I do not want to hear an ending of a movie or am in a haunted house. Probably not the most mature response, but it works when you are on the spot. Effective, sometimes funny, but not the right etiquette for work.
Over a phone conversation, it’s hard to gauge interest and engagement. You cannot tell if your clients have their fingers in their ears or their mouth partly open trying to find a point to interrupt. Are you answering their question or are you giving your answers?
Good way to test it is to stop talking and listen. If they have called, then they have something to say. If it is more than one request, then have a means to write it down without interrupting them. Once they finish speaking (there will be silence for a couple of seconds), I go over the points or questions and answer them one by one, making sure that they have received a complete understanding and a clear answer before moving to the next one.
Did that answer your question? Does this help to understand how it works? Is this the service you were looking for? Do you have any questions on what we just reviewed? I find this a more of an effective way then interrupting or answering before you know the question.
As Judge Judy says, "You have one mouth and two ears for a reason". We are all experts in our fields. To be better influences, determining what they know versus what they need takes the power of listening.