I have heard of speecheasy and other device's that provide delayed auditory feedback. However, googling LAF, I see that they insert the microphone in your throat. That I have not heard of at all. ​ In terms of delayed auditory feedback, it didn't really work for me. It doesn't feel natural if you are someone who stutters in correlation to anxiety. Because it does not suddenly become a sudden cure. Rather a device you need to practice and learn applying just as you would with conventional speech therapy techniques. So hope you find some good insight.