When you have notes that are very close together, the result is amplitude modulation.

当您的音符非常靠近时，结果就是振幅调制。

The topics the dentist liked for the moment were amplitude modulation and frequency modulation.

目前牙医感兴趣的话题在调幅和调频。

" AM" stands for " amplitude modulation." But that's technical talk that we don't really need to understand here.

代表“amplitude modulation” 。 但这是技术话题， 我们在这里并不需要真正理解。