Date of Original Version




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Abstract or Description

An early and fundamental task that any novice in the language environment (be
that an infant learning her first language or an adult learning his second one) must
accomplish is to be able to differentiate between linguistically-relevant and linguisticallyirrelevant
information. When we look at the speech as a physical signal, we see that its
variability depends on the message that is being conveyed but also on extra-linguistic
influences such as which speaker is talking, how quickly that speaker is speaking, and
even what emotional state the speaker is in presently. Each of these sources of variability
may be important for speech processing, but for a listener to understand the linguistic
message it is crucial that he attunes to variability in speech signal that is relevant for the
meaning and discounts variability that is not. Essentially, this is a task of categorization.
Although categorization appears to be necessary to speech processing, the specific
characteristics of speech categorization depend on the language environment of the
learner. The exact same physical variability in speech signal can be linguistically
functional in one language but serve no function in another one. This has become known
as a task of phonetic categorization.


Advisor: Lori L. Holt

Department of Psychology