It has long been known that the brain preferentially processes information that we focus our attention on—a classic example is the so-called cocktail party effect.

“In an environment full of voices, music, and background noise, the brain manages to concentrate on a single voice. The other noises are not objectively quieter, but are perceived less strongly at that moment,” explains brain researcher Dr. Eric Drebitz from the University of Bremen.

The brain focuses its processing on the information that is currently relevant—in this case, the voice of the conversation partner—while other signals are received but not forwarded and processed to the same extent.