This study examines the influence of an early lateral reflection on spatial perceptual attributes and speech reception. To this aim, a diffuse reflection is compared with a specular one. Although diffusive surfaces have widespread applications in room acoustics design, the knowledge of the perceptual and behavioral outcomes of these surfaces has yet to be fully developed. Two experiments were conducted to investigate how the reflection type, its temporal delay, and its azimuth affect spatial percepts (source distance, width, and focus) and speech intelligibility (SI) in diffuse stationary noise. The experimental setup included ecological elements: field measurements, a speaker-like source directivity, and real flat and diffusive surfaces. The results indicate that the presence of a single diffuse reflection reduces the perceived distance of a frontal speech source and makes it clearer. SI is higher with a diffuse reflection than with a specular one. Perceptual and behavioral outcomes both depend on the angle of reflection given the frequency- and angular-dependent properties of the diffusing surface and the directivity of the speech source. The results are interpreted with reference to loudness and binaural cues and to the precedence effect. Implications of the findings for acoustic design are also discussed.

中文翻译：

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单个横向漫反射对空间感知和语音清晰度的影响。

这项研究研究了早期横向反射对空间感知属性和语音接收的影响。为此，将漫反射与镜面反射进行比较。尽管扩散表面在室内声学设计中得到了广泛的应用，但是关于这些表面的感知和行为结果的知识尚未得到充分发展。进行了两个实验，以研究反射类型，其时间延迟及其方位如何影响弥散平稳噪声中的空间感知（源距离，宽度和焦点）和语音清晰度（SI）。实验设置包括生态要素：现场测量，类似扬声器的声源指向性以及真实的平坦和扩散表面。结果表明，单个漫反射的存在减小了正面语音源的感知距离，并使它更加清晰。漫反射的SI高于镜面反射的SI。给定散射表面的频率和角度相关特性以及语音源的方向性，感知和行为结果均取决于反射角度。参考响度和双耳提示以及优先效果来解释结果。还讨论了发现对声学设计的影响。给定散射表面的频率和角度相关特性以及语音源的方向性，感知和行为结果均取决于反射角度。参考响度和双耳提示以及优先效果来解释结果。还讨论了发现对声学设计的影响。给定散射表面的频率和角度相关特性以及语音源的方向性，感知和行为结果均取决于反射角度。参考响度和双耳提示以及优先效果来解释结果。还讨论了发现对声学设计的影响。