Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (UMR CNRS 5287), BP 63, Université de Bordeaux, 146 rue Leo Saignat, F-33076 Bordeaux, France.
J Acoust Soc Am. 2011 Jun;129(6):3837-45. doi: 10.1121/1.3589257.
When a test sound consisting of pure tones with equal intensities is preceded by a precursor sound identical to the test sound except for a reduction in the intensity of one tone, an auditory "enhancement" phenomenon occurs: In the test sound, the tone which was previously softer stands out perceptually. Here, enhancement was investigated using inharmonic sounds made up of five pure tones well resolved in the auditory periphery. It was found that enhancement can be elicited not only by increases in intensity but also by shifts in frequency. In both cases, when the precursor and test sounds are separated by a 500-ms delay, inserting a burst of pink noise during the delay has little effect on enhancement. Presenting the precursor and test sounds to opposite ears rather than to the same ear significantly reduces the enhancement resulting from increases in intensity, but not the enhancement resulting from shifts in frequency. This difference suggests that the mechanisms of enhancement are not identical for the two types of change. For frequency shifts, enhancement may be partly based on the existence of automatic "frequency-shift detectors" [Demany and Ramos, J. Acoust. Soc. Am. 117, 833-841 (2005)].
当一个由具有相同强度的纯音组成的测试声音之前是一个与测试声音相同的前导声音，只是一个音调的强度降低时，会出现听觉“增强”现象：在测试声音中，之前较弱的音调在感知上更加突出。在这里，使用在听觉外围很好分辨的五个纯音组成的非谐波声音研究了增强现象。结果发现，不仅可以通过增加强度，还可以通过改变频率来引起增强。在这两种情况下，当前导音和测试音之间的延迟为 500 毫秒时，在延迟期间插入一个粉红噪声突发对增强几乎没有影响。将前导音和测试音呈现给相对的耳朵而不是同一耳朵，会显著降低强度增加引起的增强，但不会降低频率变化引起的增强。这种差异表明，两种类型的变化的增强机制并不相同。对于频率变化，增强可能部分基于自动“频率变化检测器”的存在[Demany 和 Ramos，J. Acoust. Soc. Am. 117, 833-841（2005）]。
