Instrumental phonetic study of the rhythm of Malay

Abstract

This thesis investigates the phonetic bases of the rhythmic properties of Malay speech. The aims of this research are twofold. First, it seeks to shed light on the rhythmic properties of a language that has not been analysed extensively for its rhythmic characteristics. In doing so, results are reported from the quantitative analyses based on a range of rhythm metrics (ΔC, %V, ΔV, rPVI and nPVI) derived from the duration consonantal and vocalic intervals within the speech signal. The second objective of the thesis is to test the validity of these rhythm metrics as a means of capturing the rhythmic properties of a language. As an initial stage in the investigation of the rhythmic characteristics of Malay, short study is reported of the phonetic correlates of stress in Malay. Stress is a concept closely related to rhythm, and the way in which stressed syllables are located and realised can contribute significantly the rhythmic characteristics of the language. A list of 12 words was produced in isolation and in sentences by three native speakers of the standard variety of Malay. The words were divided into three categories: disyllabic monomorphemic words, polysyllabic monomorphemic words and polysyllabic morphologically complex words. The results reveal that in words produced in isolation, duration was found to correlate with stress; word-final vowels were significantly longer than vowels in other positions for both disyllabic and polysyllabic monomorphemic word types, whilst, the penultimate vowel was significantly longer than the other vowels in morphologically complex words. However, in connected speech, it was found that these durational differences were not present. In the subsequent acoustic phonetic investigation of the rhythmic properties of Malay, the material for analysis comprised recordings of 10 sentences produced by 20 speakers of standard Malay (10 males and 10 females). The recordings were first analysed using the rhythm metrics proposed by Ramus et. al (1999) and Grabe & Low (2002). The results indicated that Malay clustered with other so-called syllable-timed languages like French and Spanish on the basis of all metrics. However, notwithstanding the overall findings for these metrics, the results revealed a large degree of variability in values across speakers and sentences, with some speakers having values in the range typical for stressed-timed languages like English. In light of this variability, further analysis was carried in order to identify any other features of the signal which might be more robust to cross-speaker and cross-sentence variability, and which might therefore offer an alternative basis for capturing the rhythmic properties of Malay. Spectrographic analysis revealed that the duration of single vowels displayed a high degree of consistency and regularity for all speakers and sentences. In order to test this finding further, the same analysis was carried out on the data from the first experiment on the properties of stress, producing a result which was consistent with that of the second experiment. The results are discussed in light of recent studies critiquing the current state of our understanding of the rhythmic properties of speech.