Morphological effects on the darkness of English intervocalic /l/

Abstract

Abstract:Articulatory and acoustic studies have provided evidence that in word-initial and word-final positions, English /l/ exhibits substantial differences in 'darkness': dark [ɫ] in word-final position is produced with a more retracted tongue dorsum and lowered tongue body than light [l] in word-initial position. The darkness of intervocalic /l/, however, is variable. While Sproat and Fujimura (1993) argue that /l/ darkness is on a continuum strongly affected by duration, Hayes (2000) maintains that the morphological status of intervocalic /l/s should affect whether they are produced as light or dark variants. In this study, ultrasound imaging is used to investigate whether the morphological affiliation of the /l/ affects the degree of tongue dorsum retraction and tongue body lowering and the acoustic characteristics of /l/ darkness. Six American English speakers produced three types of stimuli which were predicted to increase in darkness in the following order: (1) when /l/ corresponded with the onset of a suffix (e.g., flaw-less), (2) when /l/ corresponded with the final position of the stem word (e.g., tall-est), and (3) when /l/ was the final consonant of a stem word (e.g., tall). For both articulatory and acoustic measures, the predicted order was upheld. The strongest articulatory correlate of darkness was tongue body lowering, and acoustic differences were mainly manifested in F1 and normalized intensity. Phonological implications of these findings are discussed.

North American /l/ both darkens and lightens depending on morphological constituency and segmental context

“…With respect to the question of /l/-lightening, note that this set of comparisons does not include realization of /l/ in segmentally similar morpheme-internal environments where the /l/ is not adjacent to a morpheme boundary on either side (e.g., tulip). Although Lee-Kim et al (2013) are able to identify different degrees of darkness in different positions, the lack of a morpheme-internal condition means that we cannot determine whether the effect we see in these examples is due to morpheme-final darkening (potentially applying in coolest) or to morpheme-initial lightening (potentially applying in coupless), or a combination of the two.…”

“…While it is uncontroversial that the pronunciation of /l/ in English alternates between dark and light realizations, there is substantial disagreement on how to analyze this alternation. Some authors assume syllable-final darkening (Halle & Mohanan, 1985), while others assume initial lightening (Recasens, 2012); some authors assume that there is a categorical distinction between contextually determined allophones (Halle & Mohanan, 1985;Hayes, 2000), while others argue that there is a gradient phonetic scale between dark and light /l/ (e.g., Sproat & Fujimura, 1993;Lee-Kim, Davidson, & Hwang, 2013).…”

“…Consider, for example, the stimuli from a recent production study (Lee-Kim et al, 2013), aimed at testing for effects of morphological structure:…”

“…Questions of whether variation in the realization of /l/ may be due to lightening or darkening are also difficult to address with data in Lee-Kim et al (2013) because realization of /l/ was only investigated in words in which a reduced vowel follows. Prior research has shown that the quality of the surrounding vowels, especially the following vowel, affects the degree of darkness of /l/ (Jones, 1956, p. 90;Lehiste, 1964, p. 10).…”

Whence the fuzziness? Morphological effects in interacting sound changes in Southern British English

“…In contrast, vowels are shortened in the same segmental context when no morphological boundary intervenes, e.g., in brood (Aitken, 1981;Scobbie et al, 1999;Scobbie & Stuart-Smith, 2008). Similarly, for some accents of American English, /l/-darkening is reported to apply in canonical coda positions, but also pre-vocalically before a morphological boundary, yielding a contrast between words like hail-y and Hailey (Boersma & Hayes, 2001;Lee-Kim et al, 2013). An even more striking example, since it involves high frequency words and highly productive suffixation, involves day-s and daze in Belfast English, where the latter is pronounced with a centring diphthong, while the former has a more monophthongal quality (Harris, 1994).…”