Graphonological Levenshtein Edit Distance: Application for Automated Cognate Identification

This paper presents a methodology for calculating a modified Levenshtein edit distance between character strings, and applies it to the task of automated cognate identification from non-parallel (comparable) corpora. This task is an important stage in developing MT systems and bilingual dictionaries beyond the coverage of traditionally used aligned parallel corpora, which can be used for finding translation equivalents for the ‘long tail’ in Zipfian distribution: low-frequency and usually unambiguous lexical items in closely-related languages (many of those often under-resourced). Graphonological Levenshtein edit distance relies on editing hierarchical representations of phonological features for graphemes (graphonological representations) and improves on phonological edit distance proposed for measuring dialectological variation. Graphonological edit distance works directly with character strings and does not require an intermediate stage of phonological transcription, exploiting the advantages of historical and morphological principles of orthography, which are obscured if only phonetic principle is applied. Difficulties associated with plain feature representations (unstructured feature sets or vectors) are addressed by using linguistically-motivated feature hierarchy that restricts matching of lower-level graphonological features when higher-level features are not matched. The paper presents an evaluation of the graphonological edit distance in comparison with the traditional Levenshtein edit distance from the perspective of its usefulness for the task of automated cognate identification. It discusses the advantages of the proposed method, which can be used for morphology induction, for robust transliteration across different alphabets (Latin, Cyrillic, Arabic, etc.) and robust identification of words with non-standard or distorted spelling, e.g., in user-generated content on the web such as posts on social media, blogs and comments. Software for calculating the modified feature-based Levenshtein distance, and the corresponding graphonological feature representations (vectors and the hierarchies of graphemes’ features) are released on the author’s webpage: http://corpus.leeds.ac.uk/bogdan/phonologylevenshtein/. Features are currently available for Latin and Cyrillic alphabets and will be extended to other alphabets and languages

Deep learning assessment of syllable affiliation of intervocalic consonants

In English, a sentence like “He made out our intentions.” could be misperceived as “He may doubt our intentions.” because the coda /d/ sounds like it has become the onset of the next syllable. The nature and occurrence condition of this resyllabification phenomenon are unclear, however. Previous empirical studies mainly relied on listener judgment, limited acoustic evidence, such as voice onset time, or average formant values to determine the occurrence of resyllabification. This study tested the hypothesis that resyllabification is a coarticulatory reorganisation that realigns the coda consonant with the vowel of the next syllable. Deep learning in conjunction with dynamic time warping (DTW) was used to assess syllable affiliation of intervocalic consonants. The results suggest that convolutional neural network- and recurrent neural network-based models can detect cases of resyllabification using Mel-frequency spectrograms. DTW analysis shows that neural network inferred resyllabified sequences are acoustically more similar to their onset counterparts than their canonical productions. A binary classifier further suggests that, similar to the genuine onsets, the inferred resyllabified coda consonants are coarticulated with the following vowel. These results are interpreted with an account of resyllabification as a speech-rate-dependent coarticulatory reorganisation mechanism in speech

Children\u27s Sensitivity to Pitch Variation in Language

Children acquire consonant and vowel categories by 12 months, but take much longer to learn to interpret perceptible variation. This dissertation considers children’s interpretation of pitch variation. Pitch operates, often simultaneously, at different levels of linguistic structure. English-learning children must disregard pitch at the lexical level—since English is not a tone language—while still attending to pitch for its other functions. Chapters 1 and 5 outline the learning problem and suggest ways children might solve it. Chapter 2 demonstrates that 2.5-year-olds know pitch cannot differentiate words in English. Chapter 3 finds that not until age 4–5 do children correctly interpret pitch cues to emotions. Chapter 4 demonstrates some sensitivity between 2.5 and 5 years to the pitch cue to lexical stress, but continuing difficulties at the older ages. These findings suggest a late trajectory for interpretation of prosodic variation; throughout, I propose explanations for this protracted time-course

Speech rhythm: a metaphor?

Is speech rhythmic? In the absence of evidence for a traditional view that languages strive to coordinate either syllables or stress-feet with regular time intervals, we consider the alternative that languages exhibit contrastive rhythm subsisting merely in the alternation of stronger and weaker elements. This is initially plausible, particularly for languages with a steep ‘prominence gradient’, i.e. a large disparity between stronger and weaker elements; but we point out that alternation is poorly achieved even by a ‘stress-timed’ language such as English, and, historically, languages have conspicuously failed to adopt simple phonological remedies that would ensure alternation. Languages seem more concerned to allow ‘syntagmatic contrast’ between successive units and to use durational effects to support linguistic functions than to facilitate rhythm. Furthermore, some languages (e.g. Tamil, Korean) lack the lexical prominence which would most straightforwardly underpin prominence alternation. We conclude that speech is not incontestibly rhythmic, and may even be antirhythmic. However, its linguistic structure and patterning allow the metaphorical extension of rhythm in varying degrees and in different ways depending on the language, and that it is this analogical process which allows speech to be matched to external rhythms

From Introspection to Essence: The Auditory Nature of Inner Speech

To some it is a shallow platitude that inner speech always has an auditory-phonological component. To others, it is an empirical hypothesis with accumulating support. To yet others it is a false dogma. In this chapter, I defend the claim that inner speech always has an auditory-phonological component, confining the claim to adults with ordinary speech and hearing. It is one thing, I emphasize, to assert that inner speech often, or even typically, has an auditory-phonological component—quite another to propose that it always does. When forced to argue for the stronger point, we stand to make a number of interesting discoveries about inner speech itself, and about our means for discriminating it from other psycholinguistic phenomena. Establishing the stronger conclusion also provides new leverage on debates concerning how we should conceive of, diagnose, and explain auditory verbal hallucinations and “inserted thoughts” in schizophrenia

Broad phonetic class definition driven by phone confusions

Intermediate representations between the speech signal and phones may be used to improve discrimination among phones that are often confused. These representations are usually found according to broad phonetic classes, which are defined by a phonetician. This article proposes an alternative data-driven method to generate these classes. Phone confusion information from the analysis of the output of a phone recognition system is used to find clusters at high risk of mutual confusion. A metric is defined to compute the distance between phones. The results, using TIMIT data, show that the proposed confusion-driven phone clustering method is an attractive alternative to the approaches based on human knowledge. A hierarchical classification structure to improve phone recognition is also proposed using a discriminative weight training method. Experiments show improvements in phone recognition on the TIMIT database compared to a baseline system

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