An electromagnetic wave of audio frequency produced by atmospheric disturbances such as lightning, having a characteristically decreasing frequency responsible for a whistling sound of descending pitch in detection equipment.啸声干扰一种由于诸如闪电等大气干扰而产生的音频电磁波,具有典型的逐渐减弱频率的特征,该频减引起了检波设备中调逐渐下降的啸声