In this talk, I will present data from two projects that examined how the
phonological properties of a language (e.g., presence vs. absence of a phonemic
contrast, the number of contrastive segments, phonemic vs. allophonic contrasts,
etc.) and pragmatic factors (e.g., hyperarticulated/clear speech, narrow focus)
condition speech production. I will first discuss the interaction between
pragmatic narrow/contrastive focus and lexical contrast as factors that
condition variation in pitch and duration in Croatian and Serbian. These two
closely related dialects differ in the presence or absence of lexical
pitch-accent and vowel length contrasts. It is found that lexical pitch-accent
and vowel length contrasts influence the expression of pragmatic focus: the
phonemic contrasts are enhanced in narrow focus rather than uniformly made more
prominent.
Next, I will talk about a study of clear speech production and perception
in Croatian and English. The goal of this study is to investigate the
interaction of universal, auditory-perceptual factors, which serve to enhance
the overall acoustic salience of the speech signal, and language-specific
structural factors, which serve to enhance phonologically important contrasts in
naturally produced clear speech. The two languages exhibit structural
differences (e.g., large vs. small vowel inventories, absence vs. presence of a
vowel length contrasts, etc.) that make them well-suited for this comparison.
The results show that in both languages talkers enhance the overall saliency of
the speech signal (slower speaking rate, a wider dynamic pitch range).
Additionally, both phonemic (e.g. the vowel length contrast in Croatian) and
allophonic (e.g. the tense vs. lax vowel duration difference in English)
contrasts are enhanced in clear speech. Finally, talkers enhance contrasts even
when categories seem to be sufficiently distinct and there is little chance of
confusability (the vowel space is expanded equally in English with 11 vowels and
in Croatian with just 5 vowel qualities). The results suggest that clear speech
production is driven by the phonological properties of the language, but at the
same time all segments are hyperarticulated regardless of inventory based
considerations.
Taken together, the results of these comparisons provide a window into the
interaction of lower-level acoustic-auditory and higher-level phonological
factors in spoken language processing.
