Fletcher Annalise R, McAuliffe Megan J, Lansford Kaitlin L, Liss Julie M
Department of Communication Disorders and New Zealand Institute of Language, Brain and Behaviour, University of Canterbury, Private Bag 4800, Christchurch, Canterbury 8140, New Zealand.
School of Communication Science and Disorders, Florida State University, Tallahassee, Florida 32306, USA.
J Acoust Soc Am. 2015 Oct;138(4):2132-9. doi: 10.1121/1.4930563.
This study examined the relationship between average vowel duration and spectral vowel quality across a group of 149 New Zealand English speakers aged 65 to 90 yr. The primary intent was to determine whether participants who had a natural tendency to speak slowly would also produce more spectrally distinct vowel segments. As a secondary aim, this study investigated whether advancing age exhibited a measurable effect on vowel quality and vowel durations within the group. In examining vowel quality, both flexible and static formant extraction points were compared. Two formant measurements, from selected [ɐ:], [ i:], and [ o:] vowels, were extracted from a standard passage and used to calculate two measurements of vowel space area (VSA) for each speaker. Average vowel duration was calculated from segments across the passage. The study found a statistically significant relationship between speakers' average vowel durations and VSA measurements indicating that, on average, speakers with slower speech rates produced more acoustically distinct speech segments. As expected, increases in average vowel duration were found with advancing age. However, speakers' formant values remained unchanged. It is suggested that the use of a habitually slower speaking rate may assist speakers in maintaining acoustically distinct vowels.
本研究调查了149名年龄在65岁至90岁之间的新西兰英语使用者的平均元音时长与元音频谱质量之间的关系。主要目的是确定那些天生语速较慢的参与者是否也会发出频谱上更具辨识度的元音段。作为次要目的，本研究调查了年龄增长是否对该群体的元音质量和元音时长产生可测量的影响。在检查元音质量时，对灵活和静态的共振峰提取点进行了比较。从标准段落中提取选定的[ɐ:]、[i:]和[o:]元音的两个共振峰测量值，并用于计算每个说话者的两个元音空间面积（VSA）测量值。平均元音时长是根据段落中的片段计算得出的。研究发现，说话者的平均元音时长与VSA测量值之间存在统计学上的显著关系，这表明，平均而言，语速较慢的说话者发出的语音段在声学上更具辨识度。正如预期的那样，随着年龄的增长，平均元音时长会增加。然而，说话者的共振峰值保持不变。研究表明，习惯性地使用较慢的语速可能有助于说话者保持声学上可区分的元音。
