This year's Ig Nobel Price winners ACOUSTICS PRIZE: Kazutaka Kurihara and Koji Tsukada [JAPAN] for creating the SpeechJammer — a machine that disrupts a person's speech, by making them hear their own spoken words at a very slight delay.
REFERENCE: "SpeechJammer: A System Utilizing Artificial Speech Disturbance with Delayed Auditory Feedback", Kazutaka Kurihara, Koji Tsukada, arxiv.org/abs/1202.6106. February 28, 2012.
Their "discovery" is that you can use DAF to stop people from speaking. When people hear their own voices with a slight delay, they stop speaking. One proposed application is a portable speech jamming gun, for use in places like libraries, as a quiet way to stop people from speaking, since loud interruptions are more disruptive than the speech itself.
I glanced through the paper, and it does refer to DAF for stuttering DAF has a close relationship with stuttering. DAF leads physically unimpaired people to stutter i.e., speech jamming. On the other hand, it is known that DAF can improve stuttering , and medical DAF devices are available . We utilized DAF to develop a device that can jam remote physically unimpaired people's speech whether they want it or not. This device possesses one characteristic that is different from the usual medical DAF device; namely, the microphone and speaker are located distant from the target. [Thanks to Ora for his contribution]