The production and perception of peripheral geminate/singleton coronal stop contrasts in Arabic

Gemination is typologically common word-medially but is rare at the periphery of the word (word-initially and -finally). In line with this observation, prior research on production and perception of gemination has focused primarily on medial gemination. Much less is known about the production and perception of peripheral gemination. This PhD thesis reports on comprehensive articulatory, acoustic and perceptual investigations of geminate-singleton contrasts according to the position of the contrast in the word and in the utterance. The production component of the project investigated the articulatory and acoustic features of medial and peripheral gemination of voiced and voiceless coronal stops in Modern standard Arabic and regional Arabic vernacular dialects, as produced by speakers from two disparate and geographically distant countries, Morocco and Lebanon. The perceptual experiment investigated how standard and dialectal Arabic gemination contrasts in each word position were categorised and discriminated by three groups of non-native listeners, each differing in their native language experience with gemination at different word positions. The first experiment used ultrasound and acoustic recordings to address the extent to which word-initial gemination in Moroccan and Lebanese dialectal Arabic is maintained, as well as the articulatory and acoustic variability of the contrast according to the position of the gemination contrast in the utterance (initial vs. medial) and between the two dialects. The second experiment compared the production of word-medial and -final gemination in Modern Standard Arabic as produced by Moroccan and Lebanese speakers. The aim of the perceptual experiment was to disentangle the contribution of phonological and phonetic effects of the listeners’ native languages on the categorisation and discrimination of non-lexical Moroccan gemination by three groups of non-native listeners varying in their phonological (native Lebanese group and heritage Lebanese group, for whom Moroccan is unintelligible, i.e., non-native language) and phonetic-only (native English group) experience with gemination across the three word positions. The findings in this thesis constitute important contributions about positional and dialectal effects on the production and perception of gemination contrasts, going beyond medial gemination (which was mainly included as control) and illuminating in particular the typologically rare peripheral gemination

Production and perception of Libyan Arabic vowels

PhD ThesisThis study investigates the production and perception of Libyan Arabic (LA) vowels by native speakers and the relation between these major aspects of speech. The aim was to provide a detailed acoustic and auditory description of the vowels available in the LA inventory and to compare the phonetic features of these vowels with those of other Arabic varieties. A review of the relevant literature showed that the LA dialect has not been investigated experimentally. The small number of studies conducted in the last few decades have been based mainly on impressionistic accounts. This study consists of two main investigations: one concerned with vowel production and the other with vowel perception. In terms of production, the study focused on gathering the data necessary to define the vowel inventory of the dialect and to explore the qualitative and quantitative characteristics of the vowels contained in this inventory. Twenty native speakers of LA were recorded while reading target monosyllabic words in carrier sentences. Acoustic and auditory analyses were used in order to provide a fairly comprehensive and objective description of the vocalic system of LA. The results showed that phonologically short and long Arabic vowels vary significantly in quality as well as quantity; a finding which is increasingly being reported in experimental studies of other Arabic dialects. Short vowels in LA tend to be more centralised than has been reported for other Arabic vowels, especially with regards to short /a/. The study also looked at the effect of voicing in neighbouring consonants and vowel height on vowel duration, and the findings were compared to those of other varieties/languages. The perception part of the study explored the extent to which listeners use the same acoustic cues of length and quality in vowel perception that are evident in their production. This involved the use of continua from synthesised vowels which varied along duration and/or formant frequency dimensions. The continua were randomised and played to 20 native listeners who took part in an identification task. The results show that, when it comes to perception, Arabic listeners still rely mainly on quantity for the distinction between phonologically long and short vowels. That is, when presented with stimuli containing conflicting acoustic cues (formant frequencies that are typical of long vowels but with short duration or formant frequencies that are typical of short vowels but with long duration), listeners reacted consistently to duration rather than formant frequency. The results of both parts of the study provided some understanding of the LA vowel system. The production data allowed for a detailed description of the phonetic characteristics of LA vowels, and the acoustic space that they occupy was compared with those of other Arabic varieties. The perception data showed that production and perception do not always go hand in hand and that primary acoustic cues for the identification of vowels are dialect- and language-specific

Acoustic correlates of lexical stress in Moroccan Arabic

Presently there is no consensus regarding the interpretation and analysis of the stress system of Moroccan Arabic. This paper tests whether the acoustic realisation of syllables support one widely adopted interpretation of lexical stress, according to which stress is either penultimate or final depending on syllable weight. The experiment reports on word-initial syllables that differ in presumed stress status. Target words were embedded in a carrier sentence within a scripted mock dialogue to ensure that the measurements reflect lexical stress rather than phrase-level prominence. Results from all four acoustic parameters tested (f0, duration, Centre of Gravity and vowel quality) showed that there were no differences as a function of presumed stress status, thus failing to support an interpretation according to which stressed syllables are acoustically differentiated. We consider the results in relation to previous claims and observations, and conclude that the absence of acoustic correlates of presumed stress is compatible with the view that Moroccan Arabic lacks lexical stress

Lexical and postlexical prominence in Tashlhiyt Berber and Moroccan Arabic

Tashlhiyt Berber (Afro-Asiatic, Berber) and Moroccan Arabic (Afro-Asiatic, Semitic), two languages spoken in Morocco, have been in contact for over 1200 years. The influence of Berber languages on the lexicon and the segmental-phonological structure of Moroccan Arabic is well-documented, whereas possible similarities in the prosodic-phonological domain have not yet been addressed in detail. This thesis brings together evidence from production and perception to bear on the question whether Tashlhiyt Berber and Moroccan Arabic also exhibit convergence in the domain of phonological prominence. Experimental results are interpreted as showing that neither language has lexical prominence asymmetries in the form of lexical stress. This lack of stress in Moroccan Arabic is unlike the undisputed presence of lexical stress in most other varieties of Arabic, which in turn suggests that this aspect of the phonology of Moroccan Arabic has resulted from contact with (Tashlhiyt) Berber. A further, theoretical contribution is made with respect to the possible correspondence between lexical and postlexical prominence structure from a typological point of view. One of the tenets of the Autosegmental Metrical approach to intonation analysis holds that prominence-marking intonational events (pitch accents) associate with lexically stressed syllables. Exactly how prominence marking is achieved in languages that lack lexical stress is little-understood, and this thesis' discussion of postlexical prominence in Tashlhiyt Berber and Moroccan Arabic provides new insights that bear on this topic. A first set of production experiments investigates, for both languages, if there are acoustic correlates to what some researchers have considered to be lexically stressed syllables. It is shown that neither language exhibits consistent acoustic enhancement of presumed stressed syllables relative to unstressed syllables. The second set of production experiments reports on the prosodic characteristics of question word interrogatives in both languages. It is shown that question words are the locus of postlexical prominence-marking events that however do not exhibit association to a sub-lexical phonological unit. A final perception experiment serves the goal of showing how native speakers of Tashlhiyt Berber and Moroccan Arabic deal with the encoding of a postlexical prominence contrast that is parasitic on a lexical prominence contrast. This is achieved by means of a 'stress deafness' experiment, the results of which show that speakers of neither language can reliably encode a lexically-specified prominence difference. Results from all three types of experiment thus converge in suggesting that lexical prominence asymmetries are not specified in the phonology of either language

Similarity and Enhancement: Nasality from Moroccan Arabic Pharyngeals and Nasals

Experimental studies of the articulation, acoustics, and perception of nasal and pharyngeal consonants and adjacent vowels were conducted to investigate nasality in Moroccan Arabic (MA). The status of nasality in MA is described as coarticulatorily complex, where two phoneme types (pharyngeal segments and nasal segments) yield similar non-contrastive coarticulatory information (nasality) on adjacent vowels. The production and perception of the coarticulatory complexity of nasality in MA is the focus of this dissertation. An aerodynamic study demonstrated that nasal airflow is reliably present during the production of pharyngeal consonants, yet to a degree less than nasal consonants. This study also indicated this nasality is coarticulated on vowels adjacent to pharyngeal and nasal consonants. An acoustic study confirmed the patterns of coarticulatory nasality from nasals and pharyngeals and explored how nasality as a coarticulatory complex feature, a feature associated with two distinct segment types, affects its patterning in the language. This study reveals that vowel nasality is perceptually associated with pharyngeal, as well as nasal, consonants in MA, as evidenced by faster reaction times when vowel nasality was present in a lexical repetition task, compared to a condition where there was no vowel nasality, evidence that non-contrastive coarticulatory information is indeed perceptually informative not only in the context of phonologically nasal segments, but also in the context of pharyngeal consonants. Furthermore, there is evidence of perceptual compensation for nasality, wherein in the context of pharyngeal consonants listeners show patterns that suggest they do not \u22hear\u22 vowel nasality but rather attribute it to its source. Together, this is evidence of partial compensation since listeners retain sensitivity to and facilitation from vowel nasality, revealed by faster response times in the lexical repetition task. The results of the experiments outlined in this dissertation suggest 1) that nasality is a property of pharyngeal consonants and adjacent vowels that is highly controlled by speakers in order to maintain distinctiveness between pharyngeal and nasal consonant nasality and 2) that nasality is being utilized as a secondary, enhancement feature for pharyngeal consonants, potentially to maintain the distinctiveness of pharyngeal segments from the other guttural phonological class consonants in MA

Tonal placement in Tashlhiyt: How an intonation system accommodates to adverse phonological environments

In most languages, words contain vowels, elements of high intensity with rich harmonic structure, enabling the  perceptual retrieval of pitch. By contrast, in Tashlhiyt, a Berber language, words can be composed entirely of voiceless segments. When an utterance consists of such words, the phonetic opportunity for the execution of intonational pitch movements is exceptionally limited. This book explores in a series of production and perception experiments how these typologically rare phonotactic patterns interact with intonational aspects of linguistic structure. It turns out that Tashlhiyt allows for a tremendously flexible placement of tonal events. Observed intonational structures can be conceived of as different solutions to a functional dilemma: The requirement to realise meaningful pitch movements in certain positions and the extent to which segments lend themselves to a clear manifestation of these pitch movements

An exploration of the rhythm of Malay

In recent years there has been a surge of interest in speech rhythm. However we still lack a clear understanding of the nature of rhythm and rhythmic differences across languages. Various metrics have been proposed as means for measuring rhythm on the phonetic level and making typological comparisons between languages (Ramus et al, 1999; Grabe & Low, 2002; Dellwo, 2006) but the debate is ongoing on the extent to which these metrics capture the rhythmic basis of speech (Arvaniti, 2009; Fletcher, in press). Furthermore, cross linguistic studies of rhythm have covered a relatively small number of languages and research on previously unclassified languages is necessary to fully develop the typology of rhythm. This study examines the rhythmic features of Malay, for which, to date, relatively little work has been carried out on aspects rhythm and timing. The material for the analysis comprised 10 sentences produced by 20 speakers of standard Malay (10 males and 10 females). The recordings were first analysed using rhythm metrics proposed by Ramus et. al (1999) and Grabe & Low (2002). These metrics (∆C, %V, rPVI, nPVI) are based on durational measurements of vocalic and consonantal intervals. The results indicated that Malay clustered with other so-called syllable-timed languages like French and Spanish on the basis of all metrics. However, underlying the overall findings for these metrics there was a large degree of variability in values across speakers and sentences, with some speakers having values in the range typical of stressed-timed languages like English. Further analysis has been carried out in light of Fletcher’s (in press) argument that measurements based on duration do not wholly reflect speech rhythm as there are many other factors that can influence values of consonantal and vocalic intervals, and Arvaniti’s (2009) suggestion that other features of speech should also be considered in description of rhythm to discover what contributes to listeners’ perception of regularity. Spectrographic analysis of the Malay recordings brought to light two parameters that displayed consistency and regularity for all speakers and sentences: the duration of individual vowels and the duration of intervals between intensity minima. This poster presents the results of these investigations and points to connections between the features which seem to be consistently regulated in the timing of Malay connected speech and aspects of Malay phonology. The results are discussed in light of current debate on the descriptions of rhythm

Tonal placement in Tashlhiyt: How an intonation system accommodates to adverse phonological environments

In most languages, words contain vowels, elements of high intensity with rich harmonic structure, enabling the  perceptual retrieval of pitch. By contrast, in Tashlhiyt, a Berber language, words can be composed entirely of voiceless segments. When an utterance consists of such words, the phonetic opportunity for the execution of intonational pitch movements is exceptionally limited. This book explores in a series of production and perception experiments how these typologically rare phonotactic patterns interact with intonational aspects of linguistic structure. It turns out that Tashlhiyt allows for a tremendously flexible placement of tonal events. Observed intonational structures can be conceived of as different solutions to a functional dilemma: The requirement to realise meaningful pitch movements in certain positions and the extent to which segments lend themselves to a clear manifestation of these pitch movements

Tonal placement in Tashlhiyt: How an intonation system accommodates to adverse phonological environments

In most languages, words contain vowels, elements of high intensity with rich harmonic structure, enabling the  perceptual retrieval of pitch. By contrast, in Tashlhiyt, a Berber language, words can be composed entirely of voiceless segments. When an utterance consists of such words, the phonetic opportunity for the execution of intonational pitch movements is exceptionally limited. This book explores in a series of production and perception experiments how these typologically rare phonotactic patterns interact with intonational aspects of linguistic structure. It turns out that Tashlhiyt allows for a tremendously flexible placement of tonal events. Observed intonational structures can be conceived of as different solutions to a functional dilemma: The requirement to realise meaningful pitch movements in certain positions and the extent to which segments lend themselves to a clear manifestation of these pitch movements