Delayed Auditory Feedback

Delayed Auditory Feedback (DAF), also called delayed sidetone, is a type of altered auditory feedback that consists of extending the time between speech and auditory perception. It can consist of a device that enables a user to speak into a microphone and then hear his or her voice in headphones a fraction of a second later. Some DAF devices are hardware; DAF computer software is also available. Most delays that produce a noticeable effect are between 50-200ms. DAF usage (with a 175 millisecond delay) has been shown to induce mental stress.