Generalized Metrics for Constant Directivity
Generalized Metrics for Constant Directivity
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恒定方向性的广义度量
DOI：
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发表时间：
2019
影响因子：
1.4
通讯作者：
E. Choueiri
中科院分区：
文献类型：
--
作者：
R. Sridhar;Joseph G. Tylka;E. Choueiri
提出了用于量化换能器的极辐射（或灵敏度）模式随频率不变的程度的指标。由于目前还没有建立这种质量的衡量标准（通常称为“受控”或“恒定方向性”），因此提出了五个指标，每个指标均基于恒定方向性的常用标准：（1）灵敏度轮廓线（即频率和角度上恒定灵敏度的线）的傅立叶分析，（2）指定角度监听窗口内频谱失真的平均值，（3）失真低于指定阈值的正面区域的立体角，（4）方向性指数，以及（5）极性响应的互相关性。这些指标是针对 10 个扬声器计算的，这些扬声器根据每个指标从最恒定的指令到最少的指令进行排名。比较结果值和排名，并评估每个指标在不同应用中比较传感器的适用性。对于反射或动态聆听环境中的关键聆听应用，指标 1 似乎最合适，而对于声学处理和静态环境中的此类应用，指标 2 和 3 可能更合适。此外，对于反射或嘈杂环境中的高振幅应用（例如现场声音），指标 4 和 5 似乎最合适。
Metrics are proposed for quantifying the extent to which a transducer’s polar radiation (or sensitivity) pattern is invariant with frequency. As there is currently no established measure of this quality (often called “controlled” or “constant directivity”), five metrics, each based on commonly-used criteria for constant directivity, are proposed: (1) a Fourier analysis of sensitivity contour lines (i.e., lines of constant sensitivity over frequency and angle), (2) the average of spectral distortions within a specified angular listening window, (3) the solid angle of the frontal region with distortions below a specified threshold, (4) the standard deviation of the directivity index, and (5) cross-correlations of polar responses. These metrics are computed for 10 loudspeakers that are ranked, from most constant-directive to least, according to each metric. The resulting values and rankings are compared and the suitability of each metric for comparing transducers in different applications is assessed. For critical listening applications in reflective or dynamic listening environments, metric 1 appears most suitable, while for such applications in acoustically-treated and static environments, metrics 2 and 3 may be preferable. Furthermore, for high-amplitude applications (e.g., live sound) in reflective or noisy environments, metrics 4 and 5 appear most suitable.