Jennifer S. Pardo

Conversational Role Influences Speech Imitation

This study assessed the impact of a conscious imitation goal on phonetic convergence during conversational interaction. Twelve pairs of unacquainted talkers participated in a conversational task designed to elicit between-talker repetitions of the same lexical items. To assess the degree to which the talkers exhibited phonetic convergence during the conversational task, these repetitions were used to elicit perceptual similarity judgments provided by separate sets of listeners. In addition, perceptual measures of phonetic convergence were compared with measures of articulation rates and vowel formants. The sex of the pair of talkers and a talker’s role influenced the degree of phonetic convergence, and perceptual judgments of phonetic convergence were not consistently related to individual acoustic-phonetic attributes. Therefore, even with a conscious imitative goal, situational factors were shown to retain a strong influence on phonetic form in conversational interaction.

Measuring phonetic convergence in speech production

Phonetic convergence is defined as an increase in the similarity of acoustic-phonetic form between talkers. Previous research has demonstrated phonetic convergence both when a talker listens passively to speech and while talkers engage in social interaction. Much of this research has focused on a diverse array of acoustic-phonetic attributes, with fewer studies incorporating perceptual measures of phonetic convergence. The current paper reviews research on phonetic convergence in both non-interactive and conversational settings, and attempts to consolidate the diverse array of findings by proposing a paradigm that models perceptual and acoustic measures together. By modeling acoustic measures as predictors of perceived phonetic convergence, this paradigm has the potential to reconcile some of the diverse and inconsistent findings currently reported in the literature.

Influence of Role-Switching on Phonetic Convergence in Conversation

The current study examined phonetic convergence when talkers alternated roles during conversational interaction. The talkers completed a map navigation task in which they alternated instruction Giver and Receiver roles across multiple map pairs. Previous studies found robust effects of the role of a talker on phonetic convergence, and it was hypothesized that role-switching would either reduce the impact of role or elicit alternating patterns of role-induced conversational dominance and accommodation. In contrast to the hypothesis, the initial role assignments induced a pattern of conversational dominance that persisted throughout the interaction in terms of the amount of time spent talking—Original Givers dominated amount of time talking consistently, even when they acted as Receivers. These results indicate that conversational dominance does not necessarily follow nominal role when roles alternate, and that talkers are influenced by initial role assignment when making acoustic–phonetic adjustments in their speech.

Reflections on Phonetic Convergence: Speech Perception does not Mirror Speech Production

Since the beginnings of speech research, the issue of variability has been a central topic in the field. Until recently, solutions to this problem have focused mainly on resolving linguistic forms from variable acoustic realizations, with little systematic consideration of talker variability or social settings. However, acoustic-phonetic variability within and between talkers does not arise by chance – such variation is attributable to a variety of causes including talker physiology, dialect, affect, and social/situational factors. Studies of conversational interaction demonstrate the influence of situational factors on many aspects of spoken communication. In particular, interacting talkers converge and diverge in acoustic-phonetic form over the course of a single conversational setting. Although phonetic convergence likely reflects a close connection between speech perception and production, it is not an automatic consequence of priming mechanisms or a mirror neuron system. In studies of the neural activity associated with speech perception, it is increasingly clear that utterances are processed in separate dorsal and ventral cortical streams, one that is part of the self-regulation of spoken utterances, and another that is part of conceptual understanding. Links between perception and production appear to be part of the self-regulatory system that participates in speech production control monitoring, which makes this system a likely candidate for talker control of acoustic-phonetic variability. Whether talkers converge or diverge depends on multiple aspects of the social setting, which have a much greater influence on the form of phonetic expression than automatic links or mirror mechanisms.

Phonetic convergence across multiple measures and model talkers

This study consolidates findings on phonetic convergence in a large-scale examination of the impacts of talker sex, word frequency, and model talkers on multiple measures of convergence. A survey of nearly three dozen published reports revealed that most shadowing studies used very few model talkers and did not assess whether phonetic convergence varied across same- and mixed-sex pairings. Furthermore, some studies have reported effects of talker sex or word frequency on phonetic convergence, but others have failed to replicate these effects or have reported opposing patterns. In the present study, a set of 92 talkers (47 female) shadowed either same-sex or opposite-sex models (12 talkers, six female). Phonetic convergence was assessed in a holistic AXB perceptual-similarity task and in acoustic measures of duration, F0, F1, F2, and the F1 × F2 vowel space. Across these measures, convergence was subtle, variable, and inconsistent. There were no reliable main effects of talker sex or word frequency on any measures. However, female shadowers were more susceptible to lexical properties than were males, and model talkers elicited varying degrees of phonetic convergence. Mixed-effects regression models confirmed the complex relationships between acoustic and holistic perceptual measures of phonetic convergence. In order to draw broad conclusions about phonetic convergence, studies should employ multiple models and shadowers (both male and female), balanced multisyllabic items, and holistic measures. As a potential mechanism for sound change, phonetic convergence reflects complexities in speech perception and production that warrant elaboration of the underspecified components of current accounts.

A comparison of phonetic convergence in conversational interaction and speech shadowing

Abstract Phonetic convergence is a form of variation in speech production in which a talker adopts aspects of another talker’s acoustic–phonetic repertoire. To date, this phenomenon has been investigated in non-interactive laboratory tasks extensively and in conversational interaction to a lesser degree. The present study directly compares phonetic convergence in conversational interaction and in a non-interactive speech shadowing task among a large set of talkers who completed both tasks, using a holistic AXB perceptual similarity measure. Phonetic convergence occurred in a new role-neutral conversational task, exhibiting a subtle effect with high variability across talkers that is typical of findings reported in previous research. Conversational phonetic convergence did not differ by talker sex on average, but relationships between speech shadowing and conversational convergence differed according to talker sex, with female talkers showing no consistency across settings in their relative levels of convergence and male talkers showing a modest relationship. These findings indicate that phonetic convergence is not directly compatible across different settings, and that phonetic convergence of female talkers in particular is sensitive to differences across different settings. Overall, patterns of acoustic–phonetic variation and convergence observed both within and between different settings of language use are inconsistent with accounts of automatic perception-production integration.

Short-term perceptual tuning to talker characteristics

ABSTRACT When a listener encounters an unfamiliar talker, the ensuing perceptual accommodation to the unique characteristics of the talker has two aspects: (1) the listener assesses acoustic characteristics of speech to resolve the properties of the talkers sound production; and, (2) the listener appraises the talkers idiolect, subphonemic phonetic properties that compose the finest grain of linguistic production. A new study controlled a listeners exposure to determine whether the perceptual benefit rests on specific segmental experience. Effects of sentence exposure were measured using a spoken word identification task of Easy words (likely words drawn from sparse neighbourhoods of less likely words) and Hard words (less likely words drawn from dense neighbourhoods of more likely words). Recognition of words was facilitated by exposure to voiced obstruent consonants. Overall, these findings indicate that talker-specific perceptual tuning might depend more on exposure to phonemically marked consonants than to exposure distributed across the phoneme inventory.

The Montclair Map Task: Balance, Efficacy, and Efficiency in Conversational Interaction

This paper introduces a conversational speech corpus collected during the completion of a map-matching task that is available for research purposes via the Montclair State University Digital Commons Data Repository. The Montclair Map Task is a new, role-neutral conversational task that involves paired iconic maps with labeled landmarks and a path drawn from a start point, around various landmarks, to a finish mark. One advantage of this task-oriented corpus is the ability to derive independent objective measures of task performance for both members of a conversational pair that can be related to aspects of communicative style. A total of 96 native English speakers completed the task in 16 same-sex female, 16 same-sex male, and 16 mixed-sex pairings. Conversations averaged 32 minutes in duration, yielding approximately 217,000 words. The transcription protocol delineates events such as speaking turns, inter-turn intervals, landmark phrases, fillers, pauses, overlaps, and backchannels, making this corpus a useful tool for investigating dynamics of conversational interaction. Analyses of communication efficacy and efficiency reveal that male pairs of talkers were less efficient than female and mixed-sex pairs with respect to partner map-matching task performance.

Catching the Drift: Carol A. Fowler on Phonetic Variation and Imitation

ABSTRACT In Carol Fowlers Direct Realist account of speech perception, linguistically significant gestures of the vocal tract are a common currency for both speech perception and production. A straightforward prediction of this account is that listeners will produce what they perceive, leading to imitation or gestural drift. Many studies by Fowler and colleagues have established gestural imitation across acoustic, perceptual, and articulatory measures and provided a valuable framework for understanding phonetic form variation and imitation. As such, this frameworks enduring legacy will continue to enrich an understanding of phonetic form variation in spoken communication. This article reviews Fowlers pioneering work on these issues and some of the work that it has inspired.