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Echoic memory is a short-term memory that allows the brain to hold an exact copy of what is heard for about two to four seconds. It is compared to visual or iconic memory, with echoic memory being much longer. Ulric Neisser conducted foundational research on this type of memory, and further studies have revealed new insights into its functions. The inability to retain copies of sounds for short periods has been linked to speech impairment and communication deficits.
Echoic memory, or auditory sensory memory, is part of short-term memory and refers to the way the brain can take an exact copy of what is heard and hold it for very short periods, about two to four seconds. The term is attributed to Ulric Neisser, and he is also best known for doing the foundational research on this form of remembrance. Since Neisser’s work, further studies of this type of memory continue to reveal new insights into its functions.
When a person hears a sound, such as a few notes of music or a short phrase, echoic memory is activated and the brain maintains a perfect replica of that sound for a short time. People can even defer attention to the meaning of the sound when they hear it and might interpret the brain copy instead. For example, sometimes one person doesn’t pay as much attention to another’s conversation. He might ask a speaker to repeat something and then realize he knows what was said before the speaker can repeat it. This is echoic memory in action, producing the sound copy so that the person can catch up on listening or be able to think briefly about the meaning of a sound.
Auditory short-term memory is often compared to visual or iconic memory. This is the brain’s ability to keep exact copies of an image. Comparatively, auditory sensory memory is much longer. Iconic memory lasts less than a second, while echoic memory can play a short sound of up to four seconds.
George Sperling conducted the first studies of iconic memory in the 1960s. These became the model for evaluating this type of memory. In 1967, Ulric Neisser designed tests and reporting strategies similar to those used by Sperling, in order to obtain descriptive information about auditory sensory memory.
What Neisser found is that people may be able to recall exactly up to two seconds of auditory information. Also, each audio copy could exist for up to four seconds. Subsequently, the scientists gained access to specialized brain scanning equipment and designed experiments to visualize areas of the brain associated with echoic memory. The greatest activity during tests of this type was in the prefrontal cortex, which is where most other auditory signals are processed.
Other research on auditory short-term memory has shown that people seem to increase their echoic memory up to a second higher as they get older. Thus, a child’s auditory sensory memory is not as long as that of an adolescent. However, some of this ability to produce and retain sound copies tends to deteriorate with advanced aging.
The researchers are also focused on the implication of having impaired echoic memory. The inability to retain copies of sounds for short periods has been linked to speech impairment. Individuals who lack this feature may also suffer from a variety of communication deficits.
