I'm not actually at The Call stage yet, but I am querying, and it occurs to me that if an agent is interested in my book and wants to schedule The Call, I don't know how to handle it. You see, I'm mute. I don't speak. I'm non-verbal. So phone calls are not something I can do.
How should I deal with this if or when it comes up?
I don't think this should be a problem at all in these days of modern technology. You just need to be honest with the agent about the fact you're non-verbal. There are numerous different platforms on which you can converse through text, rather than speaking out loud.
As someone used to navigating the world without speaking, you probably already have platforms you use to converse with others through text - Slack or Teams or Skype or Messenger (there are probably even more I've never heard of too). You will just need to agree with the agent what platform you are going to use and arrange a time for the conversation to begin.
So many people, even those who do speak, have anxiety about speaking on the telephone, I'm sure doing The Call this way is not unusual and many agents will have done this before.
So don't fret about this or let it stop you sending out those queries. If your book is good, and an agent wants to represent it, the fact you can't speak to her on the phone is not going to be a deal breaker. It's your writing she loves after all!