Today I was looking at a bunch of different psychoacoustic functions and how we could use them. I started looking at the absolute threshold of hearing or ATH (a data set showing the lowest audible decibel of each frequency.) I hope to use it to ignore and not graph all the data we get that is inaudible. For now we accomplish that by ignoring the bottom 10% of a file, but this still leaves a lot of spill since higher frequencies are inaudible at much higher decibels. I first got off topic and looked at the equal-loudness contour which uses A-Weighting (a curve that tries to mimic the ATH) to make everything in an audio file (almost) the same volume. There is a check box now that will show that though I'm not sure that this is relevant or useful.
I am working on using the A-Weighting curve to determine if a point is audible or not. Currently, it does find some points that aren't audible and paints them white so I can see where they are, but a many points that should come back as inaudible don't. I think there is a flaw in my decibel conversion. Once this gets working, the BeatFinder should be much more accurate since we won't have to worry about spill as much.
Slow day today, but it should lead to something useful eventually. More research in psychoacoustics and testing of decibel converters and threshold functions tomorrow.
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