"Nature," said the ancient Greek philosopher Zeno, "has given man one tongue, but two ears, that we may hear twice as much as we speak." In these last four demonstrations, several binaural effects will be illustrated. Listeners will need to use headphones to hear the effects properly.
There are many interesting auditory effects when acoustically different signals are presented to each ear. Four of the more salient effects have been selected for this set of demonstrations. They are the effect of binaural beats, a neural interference process; the effect of lateralization induced by an interaural time or intensity difference; the effect of binaural unmasking which allows a signal in noise to be better detectable when there is an interaural phase difference in the signal or the noise; and finally a demonstration or how two different pitches presented to separate ears are perceptually "re-arranged" into an image that is very different from the actual physical situation.