This technique, called 'Delayed Auditory Feedback', is according to psychologists almost certain to interrupt your speech, make someone stutter and then render them totally silent.
It is based on the theory that when we speak our brains need to hear what comes out of our mouths but it is unsettling and debilitating to hear it twice.
It will not cause the person pain, but it will stress them into shutting up - recreating an uncomfortable feeling that most people will have experienced when they hear their own voice echo back to them during a phone call or on Skype.
'In general, human speech is jammed by giving back to the speakers their own utterances at a delay of a few hundred milliseconds,' the scientists say in a new research paper for the National Institute of Advanced Industrial Science and Technology in Tskuba and at Ochanomizu University, both in Japan.
'This effect can disturb people without any physical discomfort, and disappears immediately by stop speaking.