Could you please explain the difference between these two?
Iconic is visual; echoic is auditory. Both are sensory stimuli.
Iconic: Visual sense; image lasts for only a fraction of a second; memory lasts for a few seconds; rarely converted to long-term storage.
Echoic: Auditory sense; sound may last for a few seconds; original memory lasts a few minutes; may be converted to long-term storage.