Hartmann W M, McMillon C D
Department of Physics and Astronomy, Michigan State University, East Lansing 48824, USA.
J Acoust Soc Am. 2001 Jan;109(1):294-305. doi: 10.1121/1.1331680.
The binaural coherence edge pitch (BICEP) is a dichotic broadband noise pitch effect similar to the binaural edge pitch (BEP). The BICEP stimulus is made by summing spectrally dense sine wave components with random phases. The interaural phase angle is a constant (0 or pi) for components with frequencies below (or above) a chosen edge frequency, and it is a random variable for the remaining components. The chosen edge frequency is a coherence edge because the noises to the two ears are mutually coherent within any band of frequencies on one side of the edge and they are mutually incoherent in any band on the other side. Pitch-matching experiments show that the BICEP exists for coherence edge frequencies between about 300 and 1000 Hz. It is matched by a pure-tone frequency that differs from the edge frequency by 5% to 10%. The matching frequency lies on the incoherent side of the edge, an important result that is consistent with the way that the equalization-cancellation model has been applied to binaural pitch effects, especially the BEP. The results of BICEP experiments depend upon whether the coherent components are presented in 0 or pi interaural phase for some listeners but not for all. The BICEP persists if the noise to one of the ears is delayed, but it becomes weaker and less well matched as the delay increases beyond 2 ms. The BICEP does not depend on whether the component amplitudes are all created equal or are given a Rayleigh distribution. Some reliable pitch sensation exists even when the component amplitudes are entirely independent in the two ears, so long as the phase coherence conditions of the BICEP stimulus are maintained. The existence of the BICEP is a challenge for current models of dichotic pitch because none of them predicts all its features.
双耳相干边缘音高（BICEP）是一种与双耳边缘音高（BEP）类似的双耳宽带噪声音高效应。BICEP刺激是通过将具有随机相位的频谱密集正弦波分量相加而产生的。对于频率低于（或高于）选定边缘频率的分量，双耳相位角是一个常数（0或π），而对于其余分量，它是一个随机变量。选定的边缘频率是一个相干边缘，因为到达两只耳朵的噪声在边缘一侧的任何频率带内相互相干，而在另一侧的任何频率带内相互不相干。音高匹配实验表明，BICEP存在于大约300至1000赫兹的相干边缘频率之间。它与一个纯音频率相匹配，该纯音频率与边缘频率相差5%至10%。匹配频率位于边缘的不相干一侧，这一重要结果与均衡抵消模型应用于双耳音高效应（尤其是BEP）的方式一致。对于一些听众而言，BICEP实验的结果取决于相干分量是以0还是π的双耳相位呈现，但并非对所有听众都如此。如果向一只耳朵呈现的噪声被延迟，BICEP仍然存在，但随着延迟增加超过2毫秒，它会变得更弱且匹配度更差。BICEP并不取决于分量幅度是否都相等或是否呈瑞利分布。即使两只耳朵中的分量幅度完全独立，只要保持BICEP刺激的相位相干条件，就会存在一些可靠的音高感觉。BICEP的存在对当前的双耳音高模型提出了挑战，因为它们中没有一个能预测其所有特征。
