As a performer I can't bear to listen to myself, even a recording of me talking, so I'd not take that advice. But I do very much agree with looking at your audience. Took me many years to get to a stage where I could do that while performing, but now I can and it very much tells me if they are engaged or bored or worse of all disinterested. I can also read the applause. I well remember how Folk audiences are kind enough to clap anyone for making an effort. But you learn to recognise that as the sound of sympathy. But you also learn to recognise and strive for that wonderful sound of applause of real appreciation, so look and listen to your audience, that should be your main reason for doing it at all