Speech understanding benefits when the signal is phase-inverted at one ear.

Evidence

In 1948, Licklider measured speech intelligibility for a particular dichotic speech stimulus. In his experiment, the same speech signal was presented to the left and right ears. In one condition, the speech signal was homophasic (identical at the two ears) and in the other the speech signal was inverted at one of the ears (antiphasic). A homophasic noise stimulus was presented simultaneously with the speech in both of the conditions. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1550

Categorization

• DEFINE: Introduces and explains the homophasic vs antiphasic experimental manipulation.