This circuit isn't really designed to control jaw movement on a skull, but I understand the frequency and filters bit. I would use that idea for simple on/off switching. Sounds like you need servos and servo controllers here.
If all you need is to turn on or off a motor or a switch, and you want to control muliple on/off cycles from one audio file, you can easily do that with tone switching. Here's how I would set it up. One channel of the stereo audio would contain the straight audio that eveyone would hear.
The other channel would contain the different tones. The VU meter switches I talk about in this post would all have their inputs hooked to the output of the 'Tone" channel, but that output would go into a filter first.
Something similar to a low-pass filter that blocks everything except bass frequencies would be used, except you would want more precise control over what frequency range would be allowed through. There are circuits and schematics available online for this sort of thing. It is how electronic crossovers in stereo equipment work.
Here is my example:
you have 4 switches you want to control at different points within an audio file.
Use 4 different tones created by a tone generator. All at different frequencies. One could be 100 hz another could be 500 hz, a third 1000hz and 1500hz could be the fourth.
You would need 4 filters. Their job would be to block everything except the frequency range they are set up for.
In this example, one filter would be designed to block every frequency above 150hz. This would allow the 100 hz frequency through, but block all others. The output of your "Tone" channel would feed into that filter, and the output of that filter would feed into the audio switch you made from the VU meter. The only thing that would activate that particular switch would be frequecies below 150 hz. Therefore, if a different tone were to overlap, let's say that they 500 hz frequency also hits while the 100 hz frequency is playing....Only the 100 hz frequency would get through the filter to this particular switch and it would not "hear" any other frequencies, therefore would not react to them.
The 500 hz tone would be there, but would be blocked by that switch.
Also hooked up to the output of the "Tones" channel would be three other filters. One of them would be set to block all frequencies except those within the 400 to 600 hz range.
This second filter would feed the input of a second audio switch made from the VU meter.
That second switch would only "hear" the 500 hz tone because all other frequencies would be blocked. It would only turn on for the 500 frequency whether any other frequencies were present or not.
You would do the same for the other two filters. Each of them set to block everything except the one frequency that you want to allow through.
This would give you the on/off control for as many switches as you want, all fed from the same audio channel with as much overlap as you want.
You could even take it a step further and mix the tones right into the existing audio track. Just choose frequencies that are above or below the ability of the human ear to hear. If the filters are set up to allow those frequencies through, they should still register on the VU meter and control your switch. You might drive some neighborhood dogs crazy in the process, but it should work.
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