[4] Echoic memory encodes only moderately primitive aspects of the stimuli, for example pitch, which specifies localization to the non-association brain regions.
[5] Shortly after George Sperling's partial report studies of the visual sensory memory store, researchers began investigating its counterpart in the auditory domain.
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.
The first is the storage of words that we hear, this tends to have the capacity to retain information for 3–4 seconds before decay, which is a much longer duration than iconic memory (which is less than 1000ms).
[8] However, this model fails to provide a detailed description of the relationship between the initial sensory input and ensuing memory processes.
It suggests a pre-attentive sensory storage system that can hold a large amount of accurate information over a short period of time and consists of an initial phase input of 200-400ms and a secondary phase that transfers the information into a more long term memory store to be integrated into working memory that starts to decay after 10-20s.
[9] Following Sperling's (1960) procedures on iconic memory tasks, future researchers were interested in testing the same phenomenon for the auditory sensory store.
Echoic memory is measured by behavioural tasks where participants are asked to repeat a sequence of tones, words, or syllables that were presented to them, usually requiring attention and motivation.
Within the ventrolateral prefrontal cortex, Broca's area is the main location responsible for verbal rehearsal and the articulatory process.
The cortical areas in the brain believed to be involved with auditory sensory memory exhibited by mismatch negativity response have not been localized specifically.
[9] Researchers have found shortened echoic memory duration in former late talkers, children with precordial catch syndrome[citation needed], and oral clefts, with information decaying before 2000 ms.
Mismatch negativity was greatly reduced for temporal-parietal damaged patients when the auditory stimulus was presented to the contralateral ear of the lesion side of the brain.