The Echo - Auditory Sensory Memory

If we did not have an icon we could not recognize briefly presented information. What would happen if the sensory register for auditory information did not exist?

 

Neisser - a foreigner using the word "zeal" when he meant to say "seal"/ listening to the correction - zeal not seal, the foreigner must hold the zee sound long enough to compare it with the es sound; in the valley - heel vs. hill, etc.

recognition of prosidy - the rising tone at the end of a question ? What did you say?

Experiments similar to Sperling's icon experiments have demonstrated the existence of the echo:

Moray, Bates, and Barnett (1965) Ss listened to multiple messages simultaneously/ whole report - recall the letters/ partial report - S was visually cued to report letters spoken on the specific speakers
Findings: a greater number of letters could be recalled through the partial report procedure
Implication: one second after the auditory display, there is more information available than can be reported by the whole report procedure

Darwin, Turvey, & Carter (1972) used Sperling's partial report technique / special headphones were used to present three different messages to the S simultaneously/ after hearing the messages the S saw a visual cue and reported the letters

How long does the echo exist?

Massaro (19 ) backward masking

Ss presented with 2 tones separated by an interval; task - to identify the first tone / does the second tone mask the first.

Assumption: in order for the second tone to have an effect on identification of the first some sound must remain from the first tone when the second tone occurs

Findings: as more time elapses the second tone is less and less effective as a mask (250 msec)- the first tone decays and there is nothing left to mask

Crowder (1982a) studied the duration of the echo/ presented two vowels, one after the other, sometimes the vowels were identical other times were different but similar/ varied interstimulus interval from 1/2 sec to 5 sec/ task - report whether the letters were the same or different
Findings: performance was most accurate where less than a second occurred between presentations reaching asymptote at about 3 sec
Conclusion: duration of the echo is 3 sec

Cowan (1984) posits a short auditory store that decays in less than 1 sec and is precategorical and a longer auditory store lasting several seconds and is encoded ( Articulatory loop)

Naatanen (1986) neuroscientist who studied echoic memory using the evoked potential technique (electrons placed on the scalp record electrical signals of the brain's responding). While Ss concentrate on reading a tone is repeatedly presented, on some trials the tone frequency is changed. The new tone causes a shift in the wave pattern about 200msec after the tone is presented - the change occurs in the primary auditory cortex