Rachel E. Baker

The wildcat corpus of native-and foreign-accented english: Communicative efficiency across conversational dyads with varying language alignment profiles

This paper describes the development of the Wildcat Corpus of native- and foreign-accented English, a corpus containing scripted and spontaneous speech recordings from 24 native speakers of American English and 52 non-native speakers of English. The core element of this corpus is a set of spontaneous speech recordings, for which a new method of eliciting dialogue-based, laboratory-quality speech recordings was developed (the Diapix task). Dialogues between two native speakers of English, between two non-native speakers of English (with either shared or different L1s), and between one native and one non-native speaker of English are included and analyzed in terms of general measures of communicative efficiency. The overall finding was that pairs of native talkers were most efficient, followed by mixed native/non-native pairs and non-native pairs with shared L1. Non-native pairs with different L1s were least efficient. These results support the hypothesis that successful speech communication depends both on the alignment of talkers to the target language and on the alignment of talkers to one another in terms of native language background.

Variability in Word Duration as a Function of Probability, Speech Style, and Prosody

This article examines how probability (lexical frequency and previous mention), speech style, and prosody affect word duration, and how these factors interact. Participants read controlled materials in clear and plain speech styles. As expected, more probable words (higher frequencies and second mentions) were significantly shorter than less probable words, and words in plain speech were significantly shorter than those in clear speech. Interestingly, we found second mention reduction effects in both clear and plain speech, indicating that while clear speech is hyper-articulated, this hyper-articulation does not override probabilistic effects on duration. We also found an interaction between mention and frequency, but only in plain speech. High frequency words allowed more second mention reduction than low frequency words in plain speech, revealing a tendency to hypo-articulate as much as possible when all factors support it. Finally, we found that first mentions were more likely to be accented than second mentions. However, when these differences in accent likelihood were controlled, a significant second mention reduction effect remained. This supports the concept of a direct link between probability and duration, rather than a relationship solely mediated by prosodic prominence.

On the Non-Unified Nature of Scalar Implicature: An Empirical Investigation

Scalar implicaure is often offered as the exemplar of generalized conversational implicature. However, despite the wealth of literature devoted to both the phenomenon in general and to specific examples, little attention has been paid to the various factors that may influence the generation and interpretation of scalar implicatures. This study employs the “Literal Lucy” methodology developed in Larson et al. (in press) to further investigate these factors in a controlled experimental setting. The results of our empirical investigation suggest that the type of scale employed affects whether or not speakers judge a particular scalar implicature to be part of the truth-conditional meaning of an utterance. Moreover, we found that features of the conversational context in which the implicature is situated also play an important role. Specifically, we have found that the number of scalar values evoked in the discourse context plays a significant role in the interpretation of scalar implicatures generated from gradable adjective scales but not other scale types. With respect to the effects of scale type, we have found that gradable adjectives were less frequently incorporated into truth-conditional meaning than cardinals, quantificational items, and ranked orderings. Additionally, ranked orderings were incorporated less than cardinals. Thus, the results from the current study show that the interpretation of scalar implicature is sensitive to both the associated scale type and discourse context.

The Wildcat corpus of native‐ and foreign‐accented English

This paper describes the development of the Wildcat Corpus of native- and foreign-accented English,a corpus containing scripted and spontaneous speech recordings from 24 native speakers of American English and 52 non-native speakers of English.The core element of this corpus is a set of spontaneous speech recordings, for which a new method of eliciting dialogue-based, laboratory-quality speech recordings was developed (the Diapix task). Dialogues between two native speakers of English, between two non-native speakers of English (with either shared or different LIs), and between one native and one non-native speaker of English are included and analyzed in terms of general measures of communicative efficiency.The overall finding was that pairs of native talkers were most efficient, followed by mixed native/non-native pairs and non-native pairs with shared LI. Non-native pairs with different LIs were least efficient.These results support the hypothesis that successful speech communication depends both on the alignment of talkers to the target language and on the alignment of talkers to one another in terms of native language background.

Reactive Redundancy and Listener Comprehension in Direction-Giving

We explore the role of redundancy, both in anticipation of and in response to listener confusion, in task-oriented dialogue. We find that direction-givers provide redundant utterances in response to both verbal and non-verbal signals of listener confusion. We also examine the effects of prior acquaintance and visibility upon redundancy. As expected, givers use more redundant utterances overall, and more redundant utterances in response to listener questions, when communicating with strangers. We discuss our findings in relation to theories of redundancy, the balance of speaker and listener effort, and potential applications.

Second mention reduction in Indian, English, and Korean

Phonetic reduction of the second relative to the first mention of a word in a discourse (Second Mention Reduction, or SMR) is a well‐documented feature of spoken American English (AE). This phenomenon could be mediated by discourse‐level prosodic structure: second mentions are reduced because they are less likely than first mentions to be accented in AE; or it could occur independently of prosodic structure. Impressionistic studies indicate that Indian English (IE) speakers do not deaccent second mentions like AE speakers [J. Gumperz, Discourse Strategies (1982)]. Korean marks information structure through phrasing and word order rather than pitch accents. Therefore, SMR in these languages would support a direct link between lexical probability and duration. Six IE speakers read five paragraphs containing 59 repeated words, and five Korean speakers read a Korean translation of one of these paragraphs. IE speakers were significantly less likely to deaccent second mentions than AE speakers (sign‐test, p<.05...

Clarifications in spontaneous speech under three different adverse communicative situations.

Difficult communicative situations requiring clear speech are common. This study investigated whether (a) clear speech elicited by instructing talkers to read sentences clearly reflects clarifications made by talkers in spontaneous speech with communicative intent and (b) talkers modulate their clear speech according to the type of adversity under which communication takes place. Casual and clear speech from 40 Southern British English talkers was elicited in dialogues recorded while two talkers engaged in “spot the difference” picture tasks, based on the Diapix task of Bradlow and collaborators. Three types of “communication barrier” were used to elicit clear speech: in the VOC condition, one talker heard the other via a three‐channel vocoder; in the NOISE condition, one person heard the other with simultaneous babble noise; in the L2 condition one talker was a low‐proficiency non‐native speaker. Read clear speech showed more extreme changes in median F0, F0 range and speaking rate than spontaneous clear...

Word‐level rhythm in non‐native English.

Motivated by traditional rhythm class typologies, studies of language‐learners’ rhythm typically focus on the syllable or segment level. Studying word‐level rhythm lets us explore the effects of lexical features (e.g., part of speech, predictability) on word durations in non‐native speech. This study examined whether native and non‐native English can be distinguished by variation in the realization of English lexical features, and whether non‐native‐like word‐level rhythm leads to a stronger foreign accent. Word durations were measured in English paragraphs read by 12 native American English (AE), 20 native Korean, and 20 native Chinese speakers. AE listeners rated the “accentedness” of these speakers. AE speakers showed greater within‐speaker word duration variance than non‐natives, and non‐native speakers with greater variance received more native‐like accent ratings. Increased AE variance had two causes. AE speakers had shorter relative durations for function words than non‐natives. AE speakers also showed greater variance in their content word durations than non‐natives, perhaps due to differences between words with and without pitch accents. However, both AE and non‐native speakers produced shorter second mentions of words than first mentions, showing sensitivity to lexical predictability. Overall, these findings implicate word‐level rhythm as an important and complex feature of foreign‐accented English.

Perception of phonemically‐identical true prefixes and pseudo‐prefixes in real words heard in noise

This experiment assessed the perceptual salience of acoustic‐phonetic differences measured in the first syllables of words with initial syllables that differ in morphological, but not phonemic structure [Baker et al., Proc. 16th ICPhS (2007)]. Words began with true prefixes (Pr: e.g., mistimes, displease) or pseudo‐prefixes (Ps: e.g., mistakes, displays). The fourth phoneme was a stop. A woman recorded sentences, identical except for the critical word, e.g., I think she distrusts/destroyed them, in scripted dialogs for naturalness. Critical syllables (mis‐, dis‐), up to but excluding the stop burst, were cross‐spliced either into the ‘‘wrong’’ context (mismatched conditions, PrPsPr, PsPrPs) or into another instance of the same sentence (controls, PrPrPr, PsPsPs). In a counterbalanced design, four groups of ten listeners each heard eight mismatched and eight control sentences in cafeteria noise (SNR 2 dB), and wrote what they heard. Errors were greater for critical words in mismatched than control sentence...