Johnson C E
Department of Communication Disorders, Auburn University, AL 36849-5232, USA.
J Speech Lang Hear Res. 2000 Feb;43(1):144-57. doi: 10.1044/jslhr.4301.144.
This study assessed the effects of reverberation, noise, and their combination on listeners' identification of consonants and vowels in naturally produced nonsense syllables presented at different sensation levels (re: speech recognition threshold). A secondary purpose of this study was to assess listeners' identification of voicing, manner, and place of articulation for consonants at 50 dB SL in the reverberation, noise, and combined conditions. Listeners, aged 6-30 years, identified consonant-vowel-consonant-vowel (CVCV) stimuli presented at four different sensation levels (re: speech recognition threshold) of 30, 40, 50, and 60 dB SL in 4 listening conditions: (a) an optimal listening situation (no reverberation, no noise), (b) reverberation only (1.3 seconds), (c) noise only (+13 dB S/N against a multitalker babble), and (d) reverberation plus noise. Results showed that all listener groups achieved maximum consonant identification performance at 50 dB SL. Vowel identification scores were unaffected by SL. Statistical analyses revealed that children's ability to identify consonants varied according to listening condition. For example, children's consonant identification abilities reached adult-like levels of performance at about age 14 years in the reverberation-only and noise-only listening conditions. However, in the reverberation-plus-noise listening condition, children's consonant identification abilities do not mature until the late teenage years. The ability to identify vowels, on the other hand, develops much earlier. A feature analysis of the consonant data showed that for all 3 features (voicing, manner, and place), identification scores were highest in the control condition, similar for the reverberation-only and noise-only conditions, and lowest in the reverberation-plus-noise condition. Voicing was easier for listeners to identify than manner or place of articulation features in reverberation and noise. Taken together, these results suggest that the ability to identify speech in reverberation and noise reaches adult-like level of performance at different ages for different components of the speech signal.
本研究评估了混响、噪声及其组合对听众识别在不同感觉级（相对于言语识别阈值）呈现的自然产生的无意义音节中辅音和元音的影响。本研究的第二个目的是评估听众在混响、噪声及组合条件下，在50 dB感觉级时对辅音的浊音、发音方式和发音部位的识别情况。年龄在6至30岁的听众，在4种聆听条件下识别在30、40、50和60 dB感觉级（相对于言语识别阈值）这4种不同感觉级呈现的辅音-元音-辅音-元音（CVCV）刺激：（a）最佳聆听情况（无混响，无噪声），（b）仅混响（1.3秒），（c）仅噪声（相对于多人交谈的嘈杂声+13 dB信噪比），以及（d）混响加噪声。结果显示，所有听众组在50 dB感觉级时辅音识别表现最佳。元音识别分数不受感觉级影响。统计分析表明，儿童识别辅音的能力因聆听条件而异。例如，在仅混响和仅噪声的聆听条件下，儿童的辅音识别能力在约14岁时达到类似成人的表现水平。然而，在混响加噪声的聆听条件下，儿童的辅音识别能力直到青少年晚期才成熟。另一方面，元音识别能力发展得要早得多。对辅音数据进行的特征分析表明，对于所有3个特征（浊音、发音方式和发音部位），在对照条件下识别分数最高，在仅混响和仅噪声条件下相似，在混响加噪声条件下最低。在混响和噪声环境中，听众识别浊音比识别发音方式或发音部位特征更容易。综上所述，这些结果表明，对于语音信号的不同成分，在混响和噪声中识别语音的能力在不同年龄达到类似成人的表现水平。
