Thank you so much, that clears part of it. My parents had not heard of heterodyning (one of them is an aircraft mechanic, the other one is avionics certified), but by looking that up I found frequency splitting and time division, which they are somewhat familiar with. The bat detector thing helped big time. because I think i found one that would work if I modify the output. My parents said they can identify the output end of the circuit, but are not sure on how much they will help me with constructing the audio part if I don't do some leg work
Basically my mom said we should now buy a already existing bat detector and work on switching the output to audio with frequency division and time expansion circuits as described on
So that leaves me 2 questions. Is it legal for me to modify someone elses design? (in my mind it is like putting a different set of headphones into an MP3 player). My second question is how much the people here can or will help me with the output circuit design, because my mom and dad both said they will, but it is starting to get into heavy engineering, and they have both been out of the field for a while.
Once again, TY, I have some new ideas now. It is just that my science project is not IF I can build this.....it is the data I record after I do, and what I do with it.