These signals produce the familiar signs of distress: trembling, perspiration and fast-moving feet, just to name three.

这些信号会产生常见的痛苦迹象：颤抖、 出汗和快速移动的脚， 仅举三例。

If the sine waves frequency is one of the components of the signal it will correlate with the signal producing a non-zero area.

如果正弦波频率是信号的组成部分之一，它将与产生非零区域的信号相关。