Think about a television or radio broadcast. You get to listen. You don’t have a choice.
Think about a seminar you’ve attended with hundreds of people in the audience. The presenter has a certain amount of content to get through in a specified period of time.
Now put yourself in the presenter’s shoes. You’ve planned how to interact with your audience, and ideally you’ve got a sense for how much time you will be doing that.
If you need to retain maximum control over your presentation, you need to be able to pick and choose what questions you respond to. Ideally you can choose questions that best support your point, best provide value to the broadest part of your audience, best set you up to be the rockstar.
The only way you can do that is to manage questions via text. This means that your best solution for letting the audience listen is having them on “listen only” mode, whether they’re on the telephone or listening over their computers.
Put the audience on “listen only” for optimum control.