利用残差网络分析普氏蹄蝠耳朵对恒频声源定向的影响

为研究恒频蝙蝠耳朵与空间定位的关系,利用深度学习算法和仿蝙蝠静态双耳接收器,分析蝙蝠耳朵对恒频声源定向的影响。首先根据普氏蹄蝠耳朵模型设计不同双耳夹角和间距的仿生双耳接收器,并从多个空间方位采集声源发射的不同频率的恒频声呐信号,然后提取双耳同步采集信号的时频图并归一化作为输入特征,最后利用残差网络实现声源定向。实验结果表明,静态双耳接收器对恒频声源的定向误差平均值基本保持在3.5°以下,但高于动态单耳接收器的定向误差;定向精度与声源频率及声源所在空间方位有关,声源位于接收器水平方向±30°范围内时,定向精度相对较高;双耳夹角和间距也会影响定向精度,且前者影响较为显著。

Influence of the external ear of Hipposideros pratti on determining the direction of constant frequency sound source using Residual Networks

To explore the relationship between the external ear and spatial localization in bats using constant frequency signals, the influence of bats’ external ear on determining the direction of constant frequency sound source was analyzed using deep learning algorithm with the help of static biomimetic binaural receiver. Firstly, a biomimetic binaural receiver with different angles and distances between two ears was designed based on the ear model of Hipposideros pratti. Constant frequency signals with different frequencies were collected from multiple spatial directions. Spectrograms of the synchronized signals received by two ears were extracted and normalized as input features. Finally, the spatial direction of the sound source was estimated using Residual Networks. Experimental results show that the average orientation error of the static binaural receiver to the constant frequency source is basically less than 3.5°, which is higher than that of dynamic monaural receiver. The orientation accuracy is related to the frequency and spatial direction of the sound source. The accuracy is relative high when the sound source is within ±30° along the horizontal direction of the receiver. Angles and distances between ears could also influence the accuracy, and the former’s effect is more significant.