• Phonetics and Speech Sciences
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• v.13 no.2
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• pp.19-25
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• 2021

It has been widely recognized that there are two varieties of lateral liquid /l/, which are light /l/ (a non-velarized allophone) and dark /l/ (a velarized allophone). However, this categorical view has been challenged in recent studies, both on articulatory and acoustic aspects. The purpose of this study is to investigate whether to consider /l/ velarization as a continuum in American English and provide supporting data. A spontaneous American English speech database called the Buckeye Speech Corpus was used for the material. The formant frequencies of /l/ in each syllable position were measured and analyzed statistically. The formant frequencies of /l/ in each syllable position, especially F2 values, were significantly different from each other. The results showed that there were other significantly different varieties of /l/ in American English, which support the continuum view on /l/ velarization. Regarding the effect of the adjacent vowel, the backness of the adjacent vowels was shown to affect the degree of /l/ velarization, regardless of the syllable position of the lateral liquid. This result will help provide a solid ground for the continuum view.

• Phonetics and Speech Sciences
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• v.16 no.1
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• pp.57-65
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• 2024

Normal pressure hydrocephalus (NPH) is a condition wherein the cerebrospinal pressure in the brain is within the normal range, but the cerebrospinal fluid increases above the normal level, causing ventriculomegaly. In patients with NPH, the articulatory system exhibits reduced mobility and range, which may affect diadochokinesis (DDK) and speech intelligibility. In this study, we investigated the characteristics of DDK, including accurate-token DDK and all-token DDK including inaccurate tokens, in patients with NPH and healthy elderly adults (HE). We also examined the classification accuracy of DDK between the two groups. Finally, we investigated whether there was a correlation between speech intelligibility and DDKs in the NPH group. The results showed that NPH and HE groups differed significantly in both accurate-token DDK and all-token DDK, and their classification accuracy was relatively high. However, there was no correlation between speech intelligibility and DDK. The findings suggest that the DDK is a useful method for sensitively assessing speech motor performance in patients with NPH.