Stop Place Contrasts before Liquids Edward Flemming MIT

Does phonology have a biological grounding? Phonology is shaped by the nature of speech perception and speech production. Speech production and speech perception depend on biological endowments. A case study adopting this approach to the analysis of a phonological pattern: Restrictions on stop place contrasts before laterals.

Restrictions on coronal-lateral clusters Many languages allow initial [pl, kl]/[bl, gl] clusters, but exclude [tl, dl] (Kawasaki 1982). E.g. English, German, Norwegian, Thai, etc English:  [b-g, p-k] contrast before [l], blue-glue, plan- clan  initial [dl-, tl-] are not possible.

Restrictions on coronal-lateral clusters This is a result of a dispreference for coronal-dorsal stop contrasts before laterals (Flemming 1995). Some languages reverse the English pattern,  [tl-, dl-] OK, but no *[kl-, gl-]. e.g. Haroi and other Chamic languages (Mudhenk & Goschnick 1977), Katu dialects (Wallace 1969) : Some languages have free variation between coronal and velar stops before lateral (but contrast elsewhere), e.g. Bolton English (Shorrocks 1998), Mong Njua (Lyman 1974)

Restrictions on coronal-dorsal contrasts before [l] Kawasaki (1982) hypothesizes that this dispreference is due to perceptual similarity of [dl-gl], [tl-kl]. General hypothesis: There is a preference for perceptually distinct contrasts.  Before [l], contrasts between coronal & dorsal stops are not very distinct. Previous evidence: Kawasaki (1982): Evidence from 1 speaker that formant transitions are very similar in [dl-, gl-]. -But bursts can be sufficient to distinguish stops.

Restrictions on coronal-dorsal contrasts before [l] Further investigate Kawasaki ’ s hypothesis through acoustic analysis of American English (and Hebrew). Hypothesis: English [dl-gl] and [tl-kl] contrasts would be less distinct than legal stop place contrasts (e.g. [bl-gl], before vowels). How do we infer the expected realization of [dl-, tl-]? Other stop-liquid clusters Medial [-dl-, -tl-] clusters [tl-, dl-] in languages that allow these clusters (e.g. Hebrew, Russian). But NB languages that allow these contrasts may realize stop- liquid clusters in a different fashion, e.g. less gestural overlap. Focus on voiced clusters (Am. English medial -tl- often realized as - ʔ l-).

Materials 6 near-minimal pairs for bl-gl, e.g. blow, glow 9 triplets for [b, d, g], each preceding the same set of nine vowels. Sentence frame ‘ Say X to me ’ Presented twice in random order 5 native speakers of American English, 4 female, 1 male. 6 near-minimal pairs for medial -dl-gl-, e.g. Ridley, wrigley Same frame, presented twice in random order 3 native speakers of American English, all female

Cues to stop place contrasts Prevocalic stops (e.g. Dorman et al 1977):  Release burst - transient + frication  Formant transitions Examine similar cues in stops preceding [l]. burst formant transitions

Measurements Formants: Measured F2 and F3 as soon as possible after the end of the burst. Burst: Burst duration - from stop release to onset of first formant. Shape of spectrum of first 6 ms of the burst.

Quantifying burst shape Measured from smoothed spectra (Hanson & Stevens 2003)  Calculate a series of seven DFTs on 3 ms windows at 1 ms intervals.  Average these spectra.

Quantifying burst shape bl bursts gl bursts Burst peak: frequency of the highest amplitude in the spectrum Amid-Ahi (cf. Suchato et al 2005) Amid = average amplitude from 1.25 kHz - 3 kHz Ahi = average amplitude from 3.5 kHz - 8 kHz midhigh

Stop-[l] clusters - formants English stops are not well differentiated by formant transitions before [l]. Initial [bl-, gl-] No significant differences in formant onsets. Medial [-dl-, -gl-] Small differences in F2 onsets -dl- seems to allow more coarticulatory influence of a preceding front vowel.

Stop-[l] clusters - formants Stops are not well differentiated by formant transitions before [l]. Similar results from a preliminary study of Hebrew initial [bl-, dl-, gl-], [pl-, tl-, kl-] clusters (3 speakers): Stops appear to be overlapped with following lateral, so formants at onset are largely determined by [l]. Effect is particularly striking for English [-dl-], since prevocalic [d] is usually characterized by relatively high F2 at release (~2100 Hz) Possibly lateral release of [d] facilitates the low F2 onset (1311 Hz)

Stop-l clusters - burst [gl] is more compact than [bl]. [gl] has a longer burst than [bl]. * p < 0.01 * * [gl] burst has a higher peak than [bl] burst. * Initial [bl-, gl-] clusters are distinguished by burst quality and duration.

Stop-l clusters - burst Medial [-dl-, -gl-] are also differentiated by their bursts. But the properties of [-dl-] bursts deviate substantially from prevocalic [d] bursts in the direction of [g]/[gl] bursts.

Lateral release The properties of the [dl] burst are expected consequences of laterally releasing [d]. Centrally released [d] burst has significant high frequency energy because it is filtered by the short cavity in front of the alveolar closure. But with lateral release, the front cavity includes the side passages opened up by lowering the sides of the tongue, and thus is significantly longer. Hence lower frequency peak, more compact burst shape.

Dispreference for [d-g] contrast before [l] Stop-[l] clusters are distinguished by burst not formant transitions. The [bl-gl] contrast is plausibly more distinct than [dl-gl] because the burst of laterally released [d] is compact like a velar burst. Not clear what leads to a preference for the labial-coronal contrast in Chamic etc. preference for homorganic clusters? bl- -dl- -gl-

Lateral release Similarity between [dl] and [gl] appears to be a result of lateral release of [d]. Lateral release may play a role in unusually low F2 onset in [dl]. Lateral release results in non-canonical [d] burst. So if [d] were not laterally released, [dl]-[gl] contrast should be more distinct.

Thanks to Patrick Jackson Jones

Stop-l clusters (ba)dly (Ba)gley

br vs. dr vs. gr - Formants Formant transitions distinguish [br, dr, gr]. * p < 0.01 * *

br vs. dr vs. gr - burst burst distinguishes [br, dr, gr] * p < 0.05 * * * * * * *