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As we know, the persistence of vision is phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina [Wiki]. Film is made based on this phenomenon in order to make people feel the motion.
I am curious whether human auditory system has the similar phenomenon. Persistence in cochlea or in the inferior colliculus. Let me call it persistence in auditory. This can help to explain the "old-plus-new" (P371 in Bregman's Auditory scene analysis) Heuristic. Old stream is persistent for a short while and the difference between present and past is thought new. There is very limited research on it, Bregman mentions kind of pitch persistence in his book (P24) and P750 reference (Persistence of a pitch-segregating echoic memeory. Journal of Experimental Psychology: Huamn Perception and Performance, 2, 531-537. Kubovy, M., and Jordan.)
This may also help to understand the different performance of people in speech recognition . Fluent listener may have long persistence time in his pre-cortex brain which can combine the feature in a longer past into a complex representation of the sound. In contrast, beginner has short persistence time in pre-cortex and it is not enough to build a feature before cortex and it asks the primary cortex to mentally keep persistence which will cost process time. So that beginner need slow speed.
It may also help on the percedence effect (P154, Wang's Computational Auditory Scene Analysis) that directional cues due to the direct sound are given a higher perceptual weighting than those due to reflected sound. This can be explained by using both persistence of auditory and old-plus-new. The direct cues is persistence for a while and it will compare to the reverberation coming later. If this is no new spectrum, the brain will think it is still the old stream rather than a new one so that to ignore the reverberation or to mask it (see the old-plus-new Heuristic).
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Controversial examples to 'old-plus-new' (P372 in Bregman's ASA book). 1: A sentence is heard as continuing through an interrupting load noise, despite the fact that the noise actually has replaced deleted phonetic material. The restroed sound is not simply a copy of what went before the noise, but an extrapolation based on the listener's knowledge of what a speaker is likely to be saying. 2. Musical scales can be resored when one note is removed and replace by a loud noise burst.
ReplyDeleteThe first example can be explained by schema-governed stream perception. This test cannot say the persistence is not exist. It only can show that cortex patch the missing data in order to maximise the perception rate.
ReplyDeleteThe second example can also be explained by the same as above.
I finally find the academic term for the persistence of auditory: echoic memory. http://www.psywww.com/intropsych/ch06_memory/echoic_memory.html
ReplyDeletea copy text from this link:
A less scientific demonstration of echoic memory is the "What did you say?" phenomenon, which goes like this:
Person #1: "What time is it?"
Person #2: "What did you say? Oh, 2:30."
The second person hears the question after asking, "What did you say?" This is due to echoic memory, which holds the sound of the question for a second or two. Even if you were not paying attention to the words when they were uttered, you can "hear" them when you turn your attention to them. This can be annoying to the person who starts repeating the question only to be interrupted by an answer.
See P151 in Bregman's ASA book for using the echoic memory to explain the end effect phenomenon.
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