Auditory Artifacts due to Switching Head-Related Transfer Functions of a Dynamic Virtual Auditory Display
Auditory Artifacts due to Switching Head-Related Transfer Functions of a Dynamic Virtual Auditory Display
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DOI：
10.1093/ietfec/e91-a.6.1320
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发表时间：
2008-06
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影响因子：
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通讯作者：
M. Otani;T. Hirahara
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文献类型：
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作者：
M. Otani;T. Hirahara
利用作者开发的软件实现的动态虚拟听觉显示（DVAD），研究了头部相关传递函数（hrtf）切换引起的听觉伪影。DVAD通过头部跟踪设备和切换hrtf来响应听者的头部旋转，为听者呈现高度逼真的3D虚拟听觉空间。DVAD在Windows XP系统上运行，不需要高性能计算机。总系统延迟（TSL），即头部运动与耳输入信号相应变化之间的延迟，是dvad的一个重要因素。我们的DVAD测得的TSL约为50 ms，足以满足实际应用和定位实验。另一个值得关注的问题是由切换hrtf引起的dvad中的听觉伪影。切换hrtf会引起合成双耳信号的波不连续，这可以被视为降低所呈现声音图像质量的咔哒噪声。使用听觉滤波器对不同的源信号和HRTF空间分辨率进行了主观测试和激励模式（epn）分析。主观测试结果表明，点击噪声感知取决于源信号和HRTF空间分辨率。此外，EPN分析表明，开关hrtf显著扭曲了关闭信号频率下的EPN。然而，这种失真被宽带宽源信号感知地掩盖，而它们不被窄带宽源信号掩盖，从而使点击噪声更可检测。较高的HRTF空间分辨率导致较小的失真。但是，根据源信号的不同，即使在0.5度的空间分辨率下，可感知的咔哒声仍然存在，这小于最小可听角（前方1度）。
Auditory artifacts due to switching head-related transfer functions (HRTFs) are investigated, using a software-implemented dynamic virtual auditory display (DVAD) developed by the authors. The DVAD responds to a listener's head rotation using a head-tracking device and switching HRTFs to present a highly realistic 3D virtual auditory space to the listener. The DVAD operates on Windows XP and does not require high-performance computers. A total system latency (TSL), which is the delay between head motion and the corresponding change of the ear input signal, is a significant factor of DVADs. The measured TSL of our DVAD is about 50 ms, which is sufficient for practical applications and localization experiments. Another matter of concern is the auditory artifact in DVADs caused by switching HRTFs. Switching HRTFs gives rise to wave discontinuity of synthesized binaural signals, which can be perceived as click noises that degrade the quality of presented sound image. A subjective test and excitation patterns (EPNs) analysis using an auditory filter are performed with various source signals and HRTF spatial resolutions. The results of the subjective test reveal that click noise perception depends on the source signal and the HRTF spatial resolution. Furthermore, EPN analysis reveals that switching HRTFs significantly distorts the EPNs at the off signal frequencies. Such distortions, however, are masked perceptually by broad-bandwidth source signals, whereas they are not masked by narrow-bandwidth source signals, thereby making the click noise more detectable. A higher HRTF spatial resolution leads to smaller distortions. But, depending on the source signal, perceivable click noises still remain even with 0.5-degree spatial resolution, which is less than minimum audible angle (1 degree in front).