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Speech Perception: Models of Spoken Word Recognition
Today’s class intends to:
1. discuss general phenomena in spoken word recognition; and
2. introduce different models of speech recognition:
a. Motor Theory
b. Cohort Model
c. Trace
Factors in spoken word recognition
1. Frequency Effect: High frequency words are recognized more easily than lowfrequency words (e.g. ophthalmologist vs. eye doctor)
2. Phonological neighborhood effect:
a. measure: number of different phoneme in a word
b. word recognition is more difficult for words for which there are many
similar sounding words in the lexicon (e.g. mail: rail, bail, wail, hail...)
3. Frequency * phonological neighborhood interaction:
 A high frequency word with low frequency neighbors is easy to recognize
(e.g. dog vs. {log, bog, ...}.
 A low-frequency word with high-frequency neighbors is more difficult to
recognize (e.g. wail vs. {tail, mail, rail, sail, ...}
4. Context effect (easier to identify word in context vs. by itself)
5. Familiarity effects
a. meaningful sentence context (easier to identify word in meaningful context
vs. meaningless context)
b. speaking rate information (better recognition of words spoken at the same
rate vs. varied rate)
c. characteristics of individual speakers (easier to recognize words in noise
when spoken by a familiar voice)
Motor Theory
1. Liberman and colleagues at Haskins Lab (1967, 1970)
2. Background assumption: speech is a special type of auditory stimulus for human
beings; when we are exposed to it, we evaluate speech, as opposed to music or other
nonspeech sounds (i.e. speech perception is innate and species specific – it is a
uniquely human property)
3. Idea: At some point in the speech perception process, speech signals are interpreted
by reference to motor speech movements
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4. Criticism: babies can perceive speech sounds while they cannot properly produce
them; mute people can understand speech perfectly well; gap between perception
and production exists.
5. McGurk Effect: integrating visual and auditory information
Cohort Model
1. Marslen-Wilson and Welsh (1978)
2. Motivation:
a. shadowing – fluent restorations
b. cross-modal priming
3. Three stages of word recognition:
“At the end of the drinking competition, the lorrydriver was the last one to sta...”
Access stage
perceptual representation used to activate lexical
items, thus generating a candidate set of items;
the cohort

Selection stage
one item only is chosen from this set

Integration stage
in which the semantic and syntactic properties of
the chosen word are utilized
4. All possible candidate words in sound sequence (i.e. the cohort) become active early
in word presentation
5. Elimination from cohort:
a. because words don’t match (bottom-up) or
b. because they are inconsistent with context (top-down)
6. Processing continues until all but one of the words are eliminated (uniqueness point)
and the survivor recognized (recognition point)
7. Criticism:
a. Human’s perception system is resilient to errors – it recovers from errors;
the current cohort model is not compatible with the recovery from errors
(once a lexical item is eliminated, it stays eliminated until the end)
8. Later development of the theory:
a. all-or-none (or on or off) elimination is replaced by gradual elimination (to
account for the ability of the system to recover from errors)
b. Role of context is less emphasized; in fact, context effect used only in the
integration level (each level is autonomous)