Echoic Memory

The purpose of echoic memory is to store audio information as the brain processes the sound. It also holds bits of audio information, which gives meaning to the overall sound.

It can be said that the echoic memory is conceptually like a "holding tank", where a sound is unprocessed (or held back) until the following sound is heard, and only then can it be made meaningful.

How Echoic Memory Works

When you hear something, your auditory nerve sends the sound to your brain. It does this by transmitting electrical signals. At this point, the sound is “raw” and unprocessed audio information.

Echoic memory occurs when this information is received and held by the brain. Specifically, it’s stored in the primary auditory cortex (PAC), which is found in both hemispheres of the brain.

The information is held in the PAC opposite of the ear that heard the sound. For instance, if you hear a sound in your right ear, the left PAC will hold the memory. But if you hear a sound through both ears, both the left and right PAC will retain the information. After a few seconds, the echoic memory moves into your short-term memory. This is where your brain processes the information and gives meaning to the sound.

The term echoic memory was coined in 1967 by Ulric NeisserOpens in new window to describe this brief representation of acoustic information. It was initially studied using similar partial report paradigms to those utilized by Sperling; however, modern neuropsychological techniques have enabled the development of estimations of the capacity, duration, and location of the echoic memory store.

Using Sperling's model as an analogue, researchers continue to apply his work to the auditory sensory store using partial and whole report experiments. They found that the echoic memory can store memories for up to 4 seconds.

However, different durations have been proposed involving how long the echoic memory stores the information once it is heard. However, different durations have been proposed for the existing echo once the hearing signal has been presented. Guttman and Julesz suggested that it may last approximately one second or less, while Eriksen and Johnson suggested that it can take up to 10 seconds.