Regular repeating actions such as sound waves, light waves, or radio waves have a certain frequency, or number of waves per second.
有规律的重复活动如声波、光波、无线电波都有一个特定的频率，或者说是每秒的波动次数。
《柯林斯英汉双解大词典》
2
It functions by analyzing the waves of the incoming sound and creating a second set of outgoing waves.
它的工作原理是分析传入声音的声波并产生新一轮向外扩散的声波。
3
Even with today's radio equipment, the messages will take minutes-sometimes hours-on their journey, because radio and light waves travel at the same limited speed of 186, 000 miles a second.