物体发声时振动的次数叫做频率，计量单位是赫兹。

The number of vibrations an object makes while it's making a sound is called its frequency, which is measured in Hertz.

youdao

物体发声时振动的次数叫做频率，计量单位是赫兹。

The number of vibrations an object makes while it's making a sound is called its frequency, which is measured in Hertz.

youdao