Studebaker G A, Sherbecoe R L, McDaniel D M, Gwaltney C A
Memphis Speech & Hearing Center, University of Memphis, Tennessee 38105, USA.
J Acoust Soc Am. 1999 Apr;105(4):2431-44. doi: 10.1121/1.426848.
The effects of intensity on monosyllabic word recognition were studied in adults with normal hearing and mild-to-moderate sensorineural hearing loss. The stimuli were bandlimited NU#6 word lists presented in quiet and talker-spectrum-matched noise. Speech levels ranged from 64 to 99 dB SPL and S/N ratios from 28 to -4 dB. In quiet, the performance of normal-hearing subjects remained essentially constant in noise, at a fixed S/N ratio, it decreased as a linear function of speech level. Hearing-impaired subjects performed like normal-hearing subjects tested in noise when the data were corrected for the effects of audibility loss. From these and other results, it was concluded that: (1) speech intelligibility in noise decreases when speech levels exceed 69 dB SPL and the S/N ratio remains constant; (2) the effects of speech and noise level are synergistic; (3) the deterioration in intelligibility can be modeled as a relative increase in the effective masking level; (4) normal-hearing and hearing-impaired subjects are affected similarly by increased signal level when differences in speech audibility are considered; (5) the negative effects of increasing speech and noise levels on speech recognition are similar for all adult subjects, at least up to 80 years; and (6) the effective dynamic range of speech may be larger than the commonly assumed value of 30 dB.
研究了强度对听力正常以及轻度至中度感音神经性听力损失的成年人单音节词识别的影响。刺激材料为在安静环境以及与说话者频谱匹配的噪声中呈现的带限NU#6单词列表。言语水平范围为64至99 dB SPL，信噪比范围为28至 -4 dB。在安静环境中，听力正常的受试者的表现基本保持恒定；在噪声环境中，在固定信噪比下，其表现随着言语水平呈线性下降。当针对可听度损失的影响对数据进行校正后，听力受损受试者的表现与在噪声环境中测试的听力正常受试者相似。从这些以及其他结果得出以下结论：(1) 当言语水平超过69 dB SPL且信噪比保持恒定时，噪声中的言语可懂度会降低；(2) 言语和噪声水平的影响是协同的；(3) 可懂度的下降可被模拟为有效掩蔽水平的相对增加；(4) 当考虑言语可听度差异时，听力正常和听力受损的受试者受到信号水平增加的影响相似；(5) 对于所有成年受试者，至少到80岁，言语和噪声水平增加对言语识别的负面影响是相似的；(6) 言语的有效动态范围可能大于通常假定的30 dB值。
