gidday,
Perhaps this can help, LiveSpectrogram_window example in these forums is good start.
I have used it to make a level trigger and also to detect at particular frequencies.
This example may help ,
look for this value, sgram[i][col] =
at this point it is the current i=(freqnumber) level
to work out freq if int bufferSize = 2048; then scale is 3000/256 = 11.71hz per step so 330hz/11.71 = 28.
so look for siglevel when i=28.
if int bufferSize =4096; then scale is 1500/256 = 5.8hz per step so 330hz/11.71 = 56.8.
so look for siglevel when i=56 or 57
this listens to audio line in so may work in real time?
kind regards algwat