qb DAF is professional Delayed Auditory Feedback. Delayed Auditory Feedback allows us to hear our voice with a slight delay. This delay allows us to give feedback from our voice in real time. By using the DAF we will improve our fluency immediately. This is because by listening to our voice we will set the right breathing and the right time, overcoming those obstacles that we would normally have encountered. To use the DAF you need to have headphones and set the delay between 50 ms and 75 ms. For those who use bluetooth headphones, there is already a delay, because the bluetooth signal takes longer to arrive than headphones with cable. Setting the delay to 0 ms will still have the delay between 50 ms and 75 ms. The DAF is very suitable for those who want to practice speak exercises, to reduce stuttering by up to 80% instantly, or those who simply want to prepare for a speech. To use the DAF it is necessary to be equipped with wired or bluetooth headphones with microphone.