Daniel R. van Niekerk

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The rapid development of concatenative speech synthesis systems in resource scarce languages requires an efficient and accurate solution with regard to automated phonetic alignment. However, in this context corpora are often minimally designed due to a lack of resources and expertise necessary for large scale development. Under these circumstances many(More)
We investigate the acoustic realisation of tone in short continuous utterances in Yorùbá. Fundamental frequency (F0) contours are extracted for automatically aligned syllables from a speech corpus of 33 speakers collected for speech recognition development. Extracted contours are processed and analysed statistically to describe acoustic properties in(More)
Pitch is a fundamental acoustic feature of speech and as such needs to be determined during the process of speech synthesis. While a range of communicative functions are attributed to pitch variation in speech of all languages, it plays a vital role in distinguishing meaning of lexical items in tone languages. As a number of factors are assumed to affect(More)
Introduction: Weisberg et al. [1] first described intergrowths of enstatite and kamacite in meteorites classified as unequilibrated enstatite chondrites. These intergrowths are often spherical and consist mostly of metal (kamacite) with euhedral enstatite crystals protruding into it or wholly enclosed within. The apparent absence of impact melt features led(More)
Language skills are essential for education and economic development. Many countries (especially in Africa) have more than one official language and even more unofficial languages. Being able to express oneself effectively in the written word is required for tertiary education. Unfortunately, cell phones are often blamed for the degradation of language(More)
Introduction: Northwest Africa (NWA) 1110 is a 118g olivine-phyric shergottite found in 2001 (at least 40g of additional small fragments have now been found) and tentatively paired with NWA 1068 [1]. We have made 8 sequential thin sections from a 1.25g piece* of NWA 1110, and are studying them by petrographic methods. Description: NWA 1110 has a porphyritic(More)
We present methods for modelling and synthesising fundamental frequency (F0) contours suitable for application in text-to-speech (TTS) synthesis of Yorùbá (an African tone language). These methods are discussed and compared with a baseline approach using the HMM-based speech synthesis system HTS. Evaluation is done by comparing tenfold cross validation(More)