Typically frequencies centered around 5000 Hz give or take a few thousand will have the loudest sound response. How loud it is depends on the amplitude of your program. At 20v on a boost, the likelihood of hearing sounds is very high.
Using settings like wobbles can add to the effect. Many higher frequencies will most likely not be heard.
One way some address the sounds, if they are not welcome, is to cover the remote with a sound dampening enclosure. Perhaps a small styrofoam box.
Covering the remotes will not affect their operation.
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