Accommodating variation: Dialects, idiolects, and speech processing

Abstract

Listeners are faced with enormous variation in pronunciation, yet they rarely have difficulty understanding speech. Although much research has been devoted to figuring out how listeners deal with variability, virtually none (outside of sociolinguistics) has focused on the source of the variation itself. The current experiments explore whether different kinds of variation lead to different cognitive and behavioral adjustments. Specifically, we compare adjustments to the same acoustic consequence when it is due to context-independent variation (resulting from articulatory properties unique to a speaker) versus context-conditioned variation (resulting from common articulatory properties of speakers who share a dialect). The contrasting results for these two cases show that the source of a particular acoustic-phonetic variation affects how that variation is handled by the perceptual system. We also show that changes in perceptual representations do not necessarily lead to changes in production.Keywords speech perception; speech production; perceptual learning; coarticulation; dialects; idiolects; language change; speech accommodationPsycholinguists have known for a half century that pronunciation varies for different reasons. For example, Liberman (1957) showed that the acoustics of stop consonants are drastically influenced by adjacent vowels, and Peterson and Barney (1952) showed that the acoustic realization of any particular vowel is influenced by the age, gender, and dialect of the speaker.Some sources of variation are due to unusual articulatory properties of a particular speaker, such as lisps or other speech impediments, or temporary physical states such as speaking with something in one's mouth or being drunk. Other types of variation reflect more general articulatory changes that result from adapting a sound to the phonetic context; such contextually-driven changes are commonly found in dialects: Boston speakers drop their /r/'s only when they occur after vowels (e.g., pahk for park); American English speakers 'flap' /t/ s that occur intervocalically at the onset of an unstressed syllable (e.g., the second /t/ in total) but they never flap the first /t/; and in the American South, /z/ often becomes [d]-like when it occurs before /n/ (for example, [bIdnIs] for business). In these and other ways, pronunciation can be highly variable.Address for correspondence: Mail: Arthur Samuel, Department of Psychology, State University of New York at Stony Brook, Stony Brook, NY 11794-2500, 631-632-7961, Email: Tanya Kraljic tkraljic@crl.ucsd.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply...

Sound change in the individual: Effects of exposure on cross-dialect speech processing

“…For example, Dahan et al (2008) and Maye et al (2008) both observed perceptual adaptation to vowel shifts after very brief exposure in the laboratory. Kraljic et al (2008) observed similar rapid adaptation to contextually-driven consonant variability. The results of these studies suggest that listeners require very little experience with a particular talker to retune their perceptual processes to accommodate potential sociolinguistic variation.…”

Behavioral and electrophysiological evidence for the impact of regional variation on phoneme perception

“…The regional variability in the speech input to which listeners are exposed thus influences the perception of vowels in their own regional accent. Hence it appears that the listeners' remarkable capacity to accommodate a wide range of accents as demonstrated in recent studies (e.g., Kraljic, Brennan, & Samuel, 2008) does not come without a cost in processing vowels in their own accent.…”

Effects of cross-language voice training on speech perception: Whose familiar voices are more intelligible?

“…A growing body of literature has shown that listeners are highly sensitive to this aspect of the speech signal (sometimes referred to as the talker dimension of the speech signal) when processing the linguistic information in the speech signal. It is well-established that known or inferred information about a talker alters segmental perception (Allen and Miller, 2004;Eisner and McQueen, 2005;Johnson, 1990;Johnson et al 1999;Kraljic et al, 2008;Kraljic and Samuel, 2005Ladefoged, 1978;Ladefoged and Broadbent, 1957), tone perception (Leather, 1983), and can generalize to novel linguistic contexts (Dahan et al, 2008;Kraljic and Samuel, 2007;Theodore et al, 2009). In addition to affecting the identification of individual segments, the talker dimension interacts with linguistic processing at higher cognitive levels.…”