Prosodic factors do not always suppress discourse or surprisal factors on word-final syllable duration in German polysyllabic words

Predictability is known to influence acoustic duration (e.g., Ibrahim et al. 2022) and
prosodic factors such as accenting and boundary-related lengthening have been
postulated to account for this effect (e.g., Aylett & Turk 2004). However, it has
also been shown that other factors such as information status or speech styles
could contribute to acoustic duration (e.g. Baker & Bradlow 2009). This raises the
question as to whether acoustic duration is primarily subject to the influence of
prosody that reflects linguistic structure including predictability. The current study
addressed this question by examining the acoustic duration of word-final syllables
in polysyllabic words in DIRNDL, a German radio broadcast corpus (e.g. Eckart
et al. 2012). We analysed polysyllabic words followed by an intermediate phrase
or an intonational phrase boundary, with or without accenting, and with given or
new information status. Our results indicate that the acoustic duration of the
word-final syllable was subject to the effect of prosodic boundary for long host words,
in line with Aylett & Turk (2004); however, we also observed additional effects of
information status, log surprisal and accenting for short host words, in line with
Baker & Bradlow (2009). These results suggest that acoustic duration is subject
to the influence of prosodic (e.g., boundary and accenting) and linguistic factors
(e.g., information status and surprisal), and that the primacy of prosodic factors
impacting on acoustic duration is further constrained by some intrinsic durational
constraints, for example word length.