Nelson D A
Audiology. 1979;18(4):279-306.
Two-tone masking of 1,000-Hz signals was investigated in 5 normally-hearing listerners. The results indicate a consistent increase in critical bandwidth with level of the two masking tones (approximately 3%/dB). Irregularities in the individual two-tone masking functions led to further investigations with a single listener. For subcritical frequency separations between masking tones, -10 dB/decade masking slopes were demonstrated along with large dips or notches in the two-tone masking functions. Both the -10 dB/decade masking slopes and the large notches were replicated in detail when only the lower-frequency tones of the two-tone masking pairs were employed as maskers. Separate masking bands were then introduced that eliminated the -10 dB/decade masking slope and the large notch. It is concluded that the two-tone masking experiment is really a single-tone experiment, and that the detection of beats, roughness, and combination tones determines the form of single-tone and two-tone masking functions. If critical bnadwidth estimates are to be obtained from these experiments, it is most appropriate to refer to those estimates as "critical bandwidths for tonal interaction".
在5名听力正常的受试者中研究了1000赫兹信号的双音掩蔽。结果表明，随着两个掩蔽音的强度增加，临界带宽持续增大（约为3%/分贝）。个体双音掩蔽函数的不规则性促使对一名受试者进行了进一步研究。对于掩蔽音之间低于临界频率的间隔，双音掩蔽函数呈现出-10分贝/十倍频程的掩蔽斜率，同时伴有大幅下降或凹陷。当仅使用双音掩蔽对中的低频音作为掩蔽音时，-10分贝/十倍频程的掩蔽斜率和大幅凹陷都被详细地重复呈现。随后引入了单独的掩蔽带，消除了-10分贝/十倍频程的掩蔽斜率和大幅凹陷。得出的结论是，双音掩蔽实验实际上是单音实验，并且拍音、粗糙度和组合音的检测决定了单音和双音掩蔽函数的形式。如果要从这些实验中获得临界带宽估计值，将这些估计值称为“音调相互作用的临界带宽”最为合适。
