Assessing Spherical Harmonics Interpolation of Time-Aligned Head-Related Transfer Functions
Assessing Spherical Harmonics Interpolation of Time-Aligned Head-Related Transfer Functions
复制标题
评估时间对准头部相关传递函数的球面谐波插值
DOI：
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
C. Pörschmann
中科院分区：
文献类型：
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作者：
Johannes M. Arend;F. Brinkmann;C. Pörschmann
耳机上的高质量空间音频再现需要具有高空间分辨率的头部相关传递函数（HRTF）。然而，获取具有大量（个体）HRTF的数据集并不总是可能的，并且使用大型数据集对于具有有限资源的实时应用可能是有问题的。因此，稀疏采样的HRTF的插值方法是极大的兴趣，与球面谐波（SH）插值变得越来越流行。然而，稀疏HRTF的SH表示遭受空间混叠和阶截断误差。为了减轻这一点，已经引入了预处理方法，该预处理方法在SH插值之前对稀疏HRTF进行时间对准。这减少了有效SH阶数，从而减少了SH插值所需的HRTF的数量。在本文中，我们提出了一个物理评估的四个国家的最先进的预处理方法，表现出非常相似的性能的方法，只有在低SH订单和对侧HRTF的显着差异。我们还使用一种选定的方法进行了听力实验，以确定感知透明插值所需的最小SH阶数。对于所选择的方法，一个稀疏的HRTF集合的顺序N × 7是足够的内插一个正面的来源提出的语音或打击。然而，对于横向源和噪声，需要更高阶。
High-quality spatial audio reproduction over headphones requires head-related transfer functions (HRTFs) with high spatial resolution. However, acquiring datasets with a large number of (individual) HRTFs is not always possible, and using large datasets can be problematic for real-time applications with limited resources. Consequently, interpolation methods for sparsely sampled HRTFs are of great interest, with spherical harmonics (SH) interpolation becoming increasingly popular. However, the SH representation of sparse HRTFs suffers from spatial aliasing and order truncation errors. To mitigate this, preprocessing methods have been introduced that time-align the sparse HRTFs before SH interpolation. This reduces the effective SH order and thus the number of HRTFs required for SH interpolation. In this paper, we present a physical evaluation of four state-of-the-art preprocessing methods, which showed very similar performance of the methods with notable differences only at low SH orders and contralateral HRTFs. We also performed a listening experiment with one selected method to determine the minimum required SH order required for perceptually transparent interpolation. For the selected method, a sparse HRTF set of order N ≈ 7 is sufficient for interpolating a frontal source presenting speech or percussion. Higher orders are, however, required for a lateral source and noise.