Univ Lyon, ENTPE, Laboratoire Génie Civil et Bâtiment, Rue Maurice Audin, F-69518 Vaulx-en-Velin Cedex, France.
Auditory Cognition and Psychoacoustics Team, Lyon Neurosciences Research Center, UCBL-CNRS-INSERM 5292, Inserm U1028, Lyon, France.
J Acoust Soc Am. 2019 Oct;146(4):2309. doi: 10.1121/1.5128325.
Sounds presented over headphones are generally perceived as internalized, i.e., originating from a source inside the head. Prior filtering by binaural room impulse responses (BRIRs) can create externalized sources. Previous studies concluded that these BRIRs need to be listener-specific to produce good externalization; however, listeners were generally facing a loudspeaker and asked to rate externalization relative to that loudspeaker, meaning that the source had to be perceived outside the head and also at the right distance. The present study investigated externalization when there is no visual source to match. Overall, lateral sources were perceived as more externalized than frontal sources. Experiment 1 showed that the perceived externalization obtained with non-individualized BRIRs measured in three different rooms was similar to that obtained with a state-of-the-art simulation using individualized BRIRs. Experiment 2 indicated that when there is no real source spectrum to match, headphone equalization does not improve externalization. Experiment 3 further showed that reverberation improved externalization only when it introduced interaural differences. Correlation analyses finally showed a close correspondence between perceived externalization and binaural cues (especially interaural coherence).
耳机中呈现的声音通常被感知为内源性的，即源自头部内部的声源。双耳房间脉冲响应 (BRIR) 的预先滤波可以产生外源性声源。先前的研究得出结论，这些 BRIR 需要针对特定听众进行过滤，才能产生良好的外源性效果；然而，听众通常面对扬声器，并被要求相对于该扬声器来评价外源性效果，这意味着声源必须被感知为在头部之外，并且距离也必须合适。本研究在没有视觉声源进行匹配的情况下调查了外源性效果。总体而言，侧向声源比正面声源被感知为更具有外源性。实验 1 表明，在三个不同房间中测量的非个性化 BRIR 获得的感知外源性效果与使用个性化 BRIR 进行的最先进模拟获得的效果相似。实验 2 表明，当没有真实源频谱进行匹配时，耳机均衡并不能改善外源性效果。实验 3 进一步表明，混响仅在引入耳间差异时才会改善外源性效果。相关分析最终表明，感知外源性效果与双耳线索（特别是耳间相干性）之间存在密切对应关系。
