Hold On, Wu-T'ou Weng: But audio research is not easy. Well-trained personnel with sensitive ears and eyes have recorded 356 different types of song from the two birds within barely a year. Moreover, within this short period, such work as comparing the songs one-by-one to find out which is preferred and at what frequency they occur does not easily yield readily tangible results.
但聲音的研究卻不容易，在訓練有素、耳清目靈的人員採集之下，僅一年，在兩個地點就錄了兩種鳥的三百五十六種叫聲，又要一一比較它們對鳴聲的偏好、頻率高低，「聽聲辨影」的工作不易在短期內見成果。