I'm trying to teach myself about the basics of feature extraction from digital signals. Specifically, I want to try monophonic then polyphonic pitch recognition. I don't have any university level math or computing science experience (I'm self-taught), so I find the formulas in many texts and websites to be a road-block because I don't understand what most of the Greek symbols mean. E.g. I had to search and find that $ \Sigma $ is called Sigma and that it means "summation"...
As a self-taught recording engineer I have a decent understanding of what needs to happen from a high level:
- Separate digital signal into component frequencies
- Analyse the relative strength of each frequency bin
- Evaluate the strongest frequencies and compare against known values to determine most likely chord
When I start trying to do any reading about these theories I can't translate it into code because I have no idea what the mathematical explanations are trying to tell me.
Maybe this is a question for a math forum, but I figured that a group of DSP enthusiasts and experts could help me fill in the gaps between my coding knowledge and my basic understanding of sound. I get that a Fast Fourier Transform takes a signal and transforms it from the time domain into the frequency domain, but I don't understand the process when I see it laid out in mathematical terms.
How does someone in my position move forward? What kind of resources exist to help someone with high-school algebra (but a "can-do" attitude!) learn enough to get comfortable with basic signal processing? Is there a less "math-intensive" way to gain an understanding of what needs to happen that could lead to a better understanding of the symbols and formulas commonly used?