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Abstract:
This presentation reports on an ongoing study of
the effects of sentence context and local acoustic structure on
the online processing of the voicing contrast in L2 with language
learners. The purpose of this study is to examine if online
speech processing in L2 is different from processing in L1.
The study is within the cross modal semantic priming paradigm and
examined how subjects categorised a target word which was
embedded in various sentential conditions: biased and neutral
semantic contexts and a control condition where the target word
in isolation was embedded in pink noise. Using the same
experimental technique, previous research has found immediate
effects of sentence context in identification tasks with L1
speakers (Borsky et al., 1998), but not in lexical decision tasks
(Borsky et al., 2000). The subjects are Norwegian learners
of English at two different levels of knowledge of the L2
language and the visual stimuli were presented in two different
temporal conditions, direct offset and slightly delayed in
relation to the prime. The target stimuli were from a
6-step GOAT to COAT continuum differing only in the temporal cue
for VOT. Subjects were told to indicate if the target word
matched the visual probe or not by pressing one of two buttons on
a response box while paying attention to both sound and the
meaning of the unfolding sentence. A computer program
recorded responses and response times. The sentences were
recorded on a CD where one channel went to the subject (via
headphones) and a tone on the second channel (inaudible to the
subjects) went to the computer and triggered the visual display
and start of the clock. Preliminary analysis of the data
shows an effect of both semantic context and VOT on phoneme
categorisation. Biased sentential contexts have faster
response times if the VOT values and corresponding target words
are congruent with the sentence context. Response times for
the neutral sentential context and pink noise condition fall
throughout the continuum from low to high VOT values, which
reflects the acoustic structure of the target word. There
is a shift in the categorisation towards the sentence bias for
low and high VOT values depending on the sentence bias.
Neutral sentential condition and pink noise have identifications
in an area between the biased contexts, which clearly indicates
the effect of context. Categorisations of extreme VOT
values are more congruent in the delayed probe position. No
other effects have been found for this condition. The
target words embedded in pink noise have faster responses
compared to the words embedded in sentential contexts.
References
Borsky, S., Tuller, B., & Shapiro, L.
(1998). "How to milk a coat:" The effects of semantic and
acoustic information on phoneme categorization. Journal
of the Acoustical Society of America, 103 (5),
2670-2676.
Borsky, S., Shapiro, L., & Tuller, B.
(2000). The temporal unfolding of local acoustic
information and sentence context. Journal of
Psycholinguistic Research, 29, 155-168.
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