There are two different (objects of reference or) meanings in

"...ใช้กับไฟฟ้าหรือวิทยุ

At what At what frequency does the sound occur?

I regularly listen to this frequency to hear my favorite music...."

Ex 1. frequency is more like to mean 'times we here the sound"; but

Ex 2. frequency is the carrier wave frequency of radio transmission.

In both examples, the sound/music may be of any frequency -- not one dead tone.

;-)