Corrigendum to Tic Tac TOE: Effects of predictability and importance on acoustic prominence in language production

The effect of hyperarticulation on speech comprehension under adverse listening conditions

Comprehension assesses a listener’s ability to construe the meaning of an acoustic signal in order to be able to answer questions about its contents, while intelligibility indicates the extent to which a listener can precisely retrieve the acoustic signal. Previous comprehension studies asking listeners for sentence-level information or narrative-level information used native listeners as participants. This is the first study to look at whether clear speech properties (e.g. expanded vowel space) produce a clear speech benefit at the word level for L2 learners for speech produced in naturalistic settings. This study explored whether hyperarticulated speech was more comprehensible than non-hyperarticulated speech for both L1 British English speakers and early and late L2 British English learners in quiet and in noise. Sixteen British English listeners, 16 native Mandarin Chinese listeners as early learners of L2 and 16 native Mandarin Chinese listeners as late learners of L2 rated hyperarticulated samples versus non-hyperarticulated samples in form of words for comprehension under four listening conditions of varying white noise level (quiet or SNR levels of + 16 dB, + 12 dB or + 8 dB) (3 × 2× 4 mixed design). Mean ratings showed all three groups found hyperarticulated speech samples easier to understand than non-hyperarticulated speech at all listening conditions. Results are discussed in terms of other findings (Uther et al., 2012) that suggest that hyperarticulation may generally improve speech processing for all language groups.

Prosody leaks into the memories of words

The average predictability (aka informativity) of a word in context has been shown to condition word duration (Seyfarth, 2014). All else being equal, words that tend to occur in more predictable environments are shorter than words that tend to occur in less predictable environments. One account of the informativity effect on duration is that the acoustic details of probabilistic reduction are stored as part of a word's mental representation. Other research has argued that predictability effects are tied to prosodic structure in integral ways. With the aim of assessing a potential prosodic basis for informativity effects in speech production, this study extends past work in two directions; it investigated informativity effects in another large language, Mandarin Chinese, and broadened the study beyond word duration to additional acoustic dimensions, pitch and intensity, known to index prosodic prominence. The acoustic information of content words was extracted from a large telephone conversation speech corpus with over 400,000 tokens and 6000 word types spoken by 1655 individuals and analyzed for the effect of informativity using frequency statistics estimated from a 431 million word subtitle corpus. Results indicated that words with low informativity have shorter durations, replicating the effect found in English. In addition, informativity had significant effects on maximum pitch and intensity, two phonetic dimensions related to prosodic prominence. Extending this interpretation, these results suggest that predictability is closely linked to prosodic prominence, and that the lexical representation of a word includes phonetic details associated with its average prosodic prominence in discourse. In other words, the lexicon absorbs prosodic influences on speech production.

Explicit and Emergent Mechanisms of Information Status

It is well established that language production and comprehension are influenced by information status, for example, whether information is given, new, topical, or predictable, and many scholars suggest that an important component of information status is keeping track of what information is in common ground (i.e., what is shared), and what is not. Information status affects both speakers' choices (e.g., word order, pronoun use, prosodic prominence) and how listeners interpret the speaker's meaning (e.g., Chafe, 1994; Prince, 1981). Although there is a wealth of scholarly work on information status (for a review, see Arnold, Kaiser, Kahn, & Kim, 2013), there is no consensus on the mechanisms by which it is used, and in fact relatively little discussion of the underlying representations and psycholinguistic mechanisms. Moreover, a major challenge to understanding information status is that its effects are notoriously variable. This study considers existing proposals about information status, focusing on two questions: (a) how is it represented; and (b) by what mechanisms is it used? I propose that it is important to consider whether representations and mechanisms can be classified as either explicit or emergent. Based on a review of existing evidence, I argue that information status representations are most likely emergent, but the mechanisms by which they are used are both explicit and emergent. This review provides one of the first considerations of information status processing across multiple domains.