«Year: 2016 On the origin of post-aspirated stops: production and perception of /s/ + voiceless stop sequences in Andalusian Spanish Ruch, Hanna; ...»
The hypothesis of a sound change in progress was explicitly addressed in Ruch and Harrington (2014). In an apparent-time study with 24 speakers of an Eastern (Granada) and 24 speakers of a Western (Seville) variety, they provided evidence for a sound change in progress from pre- to post-aspiration not only in Western, but also in Eastern Andalusian /st/-sequences: younger speakers produced words with medial /st/ (e.g., estanco ‘kiosk’ /esˈtanko/) with a long post-aspiration and a short or even absent preaspiration ([eˈthaŋko]), while older speakers showed a short post-aspiration and a longer pre-aspiration ([eˈhthaŋko]), these age-dependent differences being more marked among Seville than among Granada speakers. For younger Sevillian speakers, the long post-aspiration was additionally associated with a shorter closure duration, although the latter was still longer in /st/-sequences than in intervocalic stops (e.g., etapa ‘stage’ /eˈtapa/). A first aim of this paper is to test if the sound change from pre- to post-aspiration also affects /sp/- and /sk/-sequences.
Different scenarios have been proposed to explain the change from pre- to post-aspiration. For example, Parrell (2012) formulated an articulatory model based on acoustic data elicited in an experiment with manipulation of speech rate. The hypothesis to be tested was that a faster speech rate would be associated with a longer VOT as the result of a reorganization of the articulatory gestures from anti-phase (in pastándola, ‘grazing it’, [pahˈtandola]) to in-phase ([paˈthandola]). Acoustic data from 20 younger Seville speakers confirmed the hypothesis of longer pre-aspiration in slow speech and longer post-aspiration in fast speech. At the same time, the results demonstrated that the phenomenon of pre- and post-aspiration in Andalusian Spanish might be of a more complex nature, since some speakers produced long post-aspiration across all speech tempi, and the oral stop closure was more variable than predicted by Parrell’s (2012) model.
Another model is proposed by Torreira (2012). Here, the influence of lexical stress and speech rate on the production of /sp, st, sk/ in Western Andalusian Spanish was investigated. He tested the idea made explicit in Kessinger and Blumstein (1997) that, if post-aspiration is an acoustic cue to /sp, st, sk/ in Western Andalusian Spanish, it should be longer in stressed than in unstressed syllables, and longer in slow than in fast speech (i.e., in hyper-articulated words). Since no systematic effects were found in the data of three speakers from Cádiz, the author concluded that post-aspiration in this variety was the result of articulatory overlap rather than intended by the speaker, and that postaspiration is not a robust cue to /sp, st, sk/ sequences in Western Andalusian Spanish.
Torreira (2012) points to the long oral closure that was consistently produced by WAS speakers, which he suggests is a compensatory lengthening for the realignment of the oral closing gesture with respect to the glottal opening (Torreira, 2012, p. 61). He points to other reports of long consonants after a lenited /s/ in Western Andalusian Spanish (e.g., isla [ˈihlːa]), and suggests that overlap between a long oral gesture and the glottal gesture may be the more general production pattern for /s/ + consonants in this variety.
Yet another model that is based on acoustic and perceptual data is proposed by Ruch and Harrington (2014). Their apparent-time data of an Eastern and a Western Andalusian variety indicated that (1) pre-aspiration fades gradually over time, (2) post-aspiration increases gradually, and (3) intervocalic /t/ and /st/ sequences are distinguished systematically by closure duration and voice termination time (VTT), and also by voice onset time (VOT) for all but older Eastern Andalusian speakers. Correlation analyses within /st/-tokens indicated that, within a speaker, pre-aspiration shortening and post-aspiration lengthening are not necessarily interrelated with each other, but instead, younger WAS Ruch and Peters: On the Origin of Post-Aspirated Stops Art. 2, page 5 of 36 speakers showed a trading relationship between closure duration and VOT. Based on these findings, the authors hypothesized that closure lengthening might have arisen prior to the emergence of post-aspiration, and that, “if the sound change of post-aspiration were to lengthen further (...), post-aspiration on its own may eventually become the primary cue for distinguishing intervocalic /st/ from intervocalic /t/ in Andalusian Spanish” (Ruch & Harrington, 2014, p. 24). This interpretation contrasts with Torreira’s (2012) view of post-aspiration not as an intended cue to /sp, st, sk/ by the speaker, but as a result of articulatory overlap. A perception experiment in Argentinian Spanish (a variety of Spanish in which syllable-final /s/ is also weakened; see Aleza Izquierdo & Enguita Utrilla, 2002) showed that, even in a non-post-aspirating variety, post-aspiration is parsed with the underlying phonological /st/-sequence and serves as a perceptual cue. Based on these findings, the authors argue that an articulatory model may not entirely explain the change from pre- to post-aspiration, but instead perceptual factors may also be involved in the sound change.
The studies by Parrell (2012) and Ruch and Harrington (2014) are based on isolated words containing /st/-sequences. Torreira (2007b, 2012) and O’Neill (2010) also considered words containing /sp/- and /sk/-sequences, but did not specifically analyze the effect of place of articulation. From previous work on the realization of syllable-final /s/ in Spanish varieties, it is evident that the aspiration resulting from /s/-lenition varies according to the phonological context. In an acoustic study on Canarian Spanish, Marrero (1990) found weakened /s/ to be realized as breathy voice preceding labial and dental stops, and as voiceless aspiration preceding velar stops. Sánchez-Muñoz (2004) found /sk/-sequences in a Castilian variety to be realized more often with aspiration than /sp/or /st/-sequences, the latter being produced more frequently without aspiration. Similar observations are reported in Alther (1935, p. 121) who describes that /s/ preceding /p/ is reduced in the vast majority of cases, while /s/ preceding /t/ can be realized as [h], as a velar fricative, or may be assimilated to the subsequent stop.
Although the phonemic status of aspiration in Spanish is different from pre-aspiration in languages that have phonemic pre-aspirated stops (see Section 1.1), a view on the phonetics of pre-aspiration in such languages could also be enlightening in the case of Andalusian Spanish, especially when it comes to phonetic and auditory principles. Helgason (2002, p. 41) argues that “two phonetically similar sound sequences that differ only in terms of phonological interpretation should not respond in different ways to the same auditory constraint”. In the next section the paper will offer a brief review of the literature on the phonetics of pre-aspiration in languages that have it phonologically such as Scottish Gaelic and Icelandic, or as phonetic variants of, for instance, geminates, such as Italian or Swedish.
1.3 Place of articulation and pre-aspiration in other languages Clayton (2010, p. 165) reports pre-aspiration in Scottish Gaelic and Icelandic to be longest preceding velar stops and shortest preceding bilabial stops, confirming Ní Chasaide’s (1985) findings for pre-aspiration in Irish, Scottish Gaelic, and Icelandic. Clayton (2010, p. 192) assumes this variation to be conditioned by physiological or articulatory factors rather than being language-specific. His comparison between different phoneme inventories of various Scottish Gaelic varieties (Clayton, 2010, pp. 129–130) further shows de-aspiration to occur first among bilabial stops, and only later among alveolar stops.
Buccalization of pre-aspiration, on the other hand, is more frequent in the velar than in the alveolar and bilabial context.
Turning now to dialects that have pre-aspiration as a phonetic variant, similar patterns have been observed: a phonetic study on emerging pre-aspiration in Standard Art. 2, page 6 of 36 Ruch and Peters: On the Origin of Post-Aspirated Stops Swedish (Helgason & Ringen, 2008) reports pre-aspiration to be longer in the velar and dental than in the bilabial context. Stevens and Hajek (2004) found emerging preaspiration in Italian dialects more often preceding velar than dental geminates. This pattern may be related to articulatory constraints, as suggested by Ní Chasaide and Ó Dochartaigh (1984, p. 153) and Helgason and Ringen (2008). Helgason and Ringen (2008, pp. 623–624) argue, based on Hardcastle (1973), that the lower velocity of the tongue body movement for velars compared to coronals and bilabials might lead to a longer transition phase (i.e., pre-aspiration) between the preceding vowel and the silence due to the oral closure.
A second aim of this study is to systematically analyze the influence of place of articulation on the production of /s/ + voiceless stop sequences among older and younger speakers in two different varieties. The idea is to compare synchronic variation in the production of /sp, st, sk/ — as inferred from variation within the group of older EAS speakers — with diachronic change, which will be analyzed in terms of apparent-time comparisons between older and younger speakers in both varieties. By doing so, the paper hopes to shed light on the role of articulatory and perceptual factors in sound change actuation. The so-called actuation problem (Weinreich et al., 1968) addresses the questions of why a change takes place in a particular language at a given time, and of what factors contribute to this change (Weinreich et al., 1968, p. 102).
1.4 Sound change actuation When relating specifically to sound change, the actuation problem has been re-defined in different ways (see Stevens & Harrington, 2014, for an overview). While some authors distinguish between sound change initiation and spread, others draw the line between variation and selection of variants on the one hand and spread of change on the other (Stevens & Harrington, 2014, p. 4). In the present paper, the term sound change actuation is used when referring to the critical moment where the listener becomes speaker, or, in other words, sound change actuation is defined as the transition from initiation to spread: Why would a listener adopt a particular new pronunciation form and use it in his own speech?
Directly related to this issue is the role of articulatory as opposed to perceptual factors in sound change: Is sound change mainly speaker-driven, or is it primarily listenerdriven? Ohala’s (1993) model proposes that sound change arises from the misperception of the acoustic signal by the listener, that is, when the listener erroneously interprets the acoustic effects of coarticulation as a new sound instead of attributing it to its articulatory source. Other models, such as Articulatory Phonology (Browman & Goldstein, 1991, 1992), suggest that several types of sound change result from the variability that normally occurs in speech, namely reductions in the magnitude of articulatory gestures as well as increase in gestural overlap. When the listener fails to “correctly identify which of two overlapping gestures is the source of some aspect of the acoustic signal” Browman & Goldstein, 1991, p. 313, then sound change can arise: the listener when becoming the speaker will use a different gestural configuration for the same sound. Common to these and other views is the idea that sound change arises from synchronic variation in spoken language. While Ohala’s (1993) model focuses more on the perceptual consequences of variation in articulation, Browman and Goldstein’s (1991, 1992) main focus lies on the articulatory sources of variation.
How strong must the coarticulatory effects be in order to be perceivable and to be misinterpreted by the listener, and how strong may they be in order to be taken up by the listener? Why should a listener take up a pronunciation form that deviates Ruch and Peters: On the Origin of Post-Aspirated Stops Art. 2, page 7 of 36 from what he usually hears? Baker et al. (2011) suggest that sound change arises from the individual differences in coarticulation among speakers, arguing that “if every speaker produces essentially the same amount of coarticulation, then there is nothing to imitate in the first place” (Baker et al., 2011, p. 350). Only if the phonetic effect of coarticulation is large enough and perceptible can the listener interpret it as a different production target, and only then can it be imitated. In contrast, from an exemplar-theory (Pierrehumbert, 2001) point of view, we would expect phonetically similar productions to be imitated, and phonetically deviant productions not to be stored in the set of exemplars used for speech production (Garrett & Johnson, 2013, pp. 86–87). Slightly different, but still similar variants, on the other hand, are stored in memory and can gradually shift a cloud of exemplars in one direction and would therefore predict sound change to be accumulative.