Wilson Richard H, McArdle Rachel, Roberts Heidi
VA Medical Center, Mountain Home, TN 37684, USA.
J Am Acad Audiol. 2008 Jun;19(6):496-506. doi: 10.3766/jaaa.19.6.5.
So that portions of the classic Miller, Heise, and Lichten (1951) study could be replicated, new recorded versions of the words and digits were made because none of the three common monosyllabic word lists (PAL PB-50, CID W-22, and NU-6) contained the 9 monosyllabic digits (1-10, excluding 7) that were used by Miller et al. It is well established that different psychometric characteristics have been observed for different lists and even for the same materials spoken by different speakers. The decision was made to record four lists of each of the three monosyllabic word sets, the monosyllabic digits not included in the three sets of word lists, and the CID W-1 spondaic words. A professional female speaker with a General American dialect recorded the materials during four recording sessions within a 2-week interval. The recording order of the 582 words was random.
To determine-on listeners with normal hearing-the psychometric properties materials presented in speech-spectrum noise.
A quasi-experimental, repeated-measures design was used.
Twenty-four young adult listeners (M = 23 years) with normal pure-tone thresholds (< or = 20-dB HL at 250 to 8000 Hz) participated. The participants were university students who were unfamiliar with the test materials.
The 582 words were presented at four signal-to-noise ratios (SNRs; -7-, -2-, 3-, and 8-dB) in speech-spectrum noise fixed at 72-dB SPL. Although the main metric of interest was the 50% point on the function for each word established with the Spearman-Kärber equation (Finney, 1952), the percentage correct on each word at each SNR was evaluated. The psychometric characteristics of the PB-50, CID W-22, and NU-6 monosyllabic word lists were compared with one another, with the CID W-1 spondaic words, and with the 9 monosyllabic digits.
Recognition performance on the four lists within each of the three monosyllabic word materials were equivalent, +/- 0.4 dB. Likewise, word-recognition performance on the PB-50, W-22, and NU-6 word lists were equivalent, +/- 0.2 dB. The mean recognition performance at the 50% point with the 36 W-1 spondaic words was approximately 6.2 dB lower than the 50% point with the monosyllabic words. Recognition performance on the monosyllabic digits was 1-2 dB better than mean performance on the monosyllabic words.
Word-recognition performances on the three sets of materials (PB-50, CID W-22, and NU-6) were equivalent, as were the performances on the four lists that make up each of the three materials. Phonetic/phonemic balance does not appear to be an important consideration in the compilation of word-recognition lists used to evaluate the ability of listeners to understand speech. A companion paper examines the acoustic, phonetic/phonological, and lexical variables that may predict the relative ease or difficulty for which these monosyllable words were recognized in noise (McArdle and Wilson, this issue).
为了能够复制经典的米勒、海泽和利希滕（1951年）研究的部分内容，制作了单词和数字的新录音版本，因为三种常见的单音节单词列表（PAL PB - 50、CID W - 22和NU - 6）中都不包含米勒等人使用的9个单音节数字（1 - 10，不包括7）。众所周知，不同的列表甚至不同说话者说出的相同材料都观察到了不同的心理测量特征。因此决定录制三种单音节单词集各自的四个列表、这三组单词列表中未包含的单音节数字以及CID W - 1双音节词。一位操通用美国方言的职业女性在两周内的四个录音时段录制了这些材料。582个单词的录制顺序是随机的。
确定听力正常的听众对语音频谱噪声中呈现的材料的心理测量特性。
采用了准实验性重复测量设计。
24名年轻成年听众（平均年龄23岁）参与，他们的纯音阈值正常（250至8000赫兹时≤20分贝听力级）。参与者是不熟悉测试材料的大学生。
582个单词以四种信噪比（SNR； - 7、 - 2、3和8分贝）在固定为72分贝声压级的语音频谱噪声中呈现。尽管主要关注的指标是用斯皮尔曼 - 卡尔伯方程（芬尼，1952年）为每个单词确定的函数上的50%点，但也评估了每个信噪比下每个单词的正确百分比。将PB - 50、CID W - 22和NU - 6单音节单词列表的心理测量特征相互比较，与CID W - 1双音节词比较，以及与9个单音节数字比较。
三种单音节单词材料各自的四个列表上的识别表现相当，相差±0.4分贝。同样，PB - 50、W - 22和NU - 6单词列表上的单词识别表现相当，相差±0.2分贝。36个W - 1双音节词在50%点的平均识别表现比单音节词在50%点的表现低约6.2分贝。单音节数字的识别表现比单音节词的平均表现好1 - 2分贝。
三组材料（PB - 50、CID W - 22和NU - 6）的单词识别表现相当，构成这三种材料的四个列表的表现也相当。在编制用于评估听众理解言语能力的单词识别列表时，语音/音素平衡似乎不是一个重要考虑因素。一篇配套论文研究了可能预测这些单音节词在噪声中被识别的相对难易程度的声学、语音/音系和词汇变量（麦卡德尔和威尔逊，本期）。
