Cocktail party effect

When they are in a noisy environment, humans have the ability to focus their hearing onto one source.^[1][2] This phenomenon is called cocktail party effect. It is named after the fact that a person attending a noisy cocktail party is able to focus their listening to the conversation they are doing, and disregard the other conversations.

A crowded cocktail bar

It has been proposed that one's sensory memory subconsciously parses all stimuli and identifies discrete pieces of information by classifying them by salience.^[3] This effect is what allows most people to "tune into" a single voice and "tune out" all others. This phenomenon is often described in terms of "selective attention" or "selective hearing". It may also describe a similar phenomenon that occurs when one may immediately detect words of importance coming from unattended stimuli, for example hearing one's name among a wide range of auditory input.^[4][5]

An inability to segregate stimuli in this way is sometimes referred to as the cocktail party problem^[6] or cocktail party deafness.^[7]