Echoic memory seems to have a great impact on the process of auditive perception, as indicated by different studies. There is reason to believe that deviations in echoic persistence can cause disturbances in the process of decoding accoustic stimuli.

Short echoic memory gives less time for identification of the stimulus, which increases the need for longer duration of the stimulus.

Long echoic memory would give sufficient time for identification. However, there are some indications that long echoic memory may obstruct perception of patterns in phonemic sequences.

This research project is based on an information processing mode! in accordance with Massaro's theory. It includes three separate studies. In the first study we found that echoic persistence was inversely related to stimulus time for Tone 1, and that it decreased exponentially with increasing stimulus amplitude of Tone 2. The frequency of the two sounds does not seem to have any influence on echoic persistence.

In the second study two experiments were performed. The results reveal considerable individual differences in echoic and iconic (visual) memory, and a significant decrease in echoic persistence with age. We also found a positive correlation between the duration of echoic and iconic memory. In the second experiment, the positive correlation just mentioned was confirmed; no reliable sex differences in any age group were found.

The third study revealed a significant negative correlation between duration of echoic persistance and the ability to perceive two vowel sounds in the middle of a sequence. No positive correlation was found between echoic persistence and the ability to identify monosyllabic nonsense words.