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This example program demonstrates how to create and use an analysis gammatone filterbank
This code produces the following output:
Building a filterbank for 16276Hz sampling frequency. Lower cutoff frequency: 70Hz Upper cutoff frequency: 6700Hz Base frequency : 1000Hz filters per ERB : 1 filterbank contains 30 filters: # | f / Hz | normalization | coefficient 1| 73.223641 | 5.265982e-08 | 0.986867 + 0.027903i 2| 107.651956 | 8.085647e-08 | 0.984969 + 0.040957i 3| 146.004401 | 1.241101e-07 | 0.982654 + 0.055445i 4| 188.728245 | 1.904318e-07 | 0.979828 + 0.071514i 5| 236.321739 | 2.920749e-07 | 0.976374 + 0.089322i 6| 289.339925 | 4.477658e-07 | 0.972152 + 0.109040i 7| 348.401107 | 6.860992e-07 | 0.966986 + 0.130846i 8| 414.194064 | 1.050696e-06 | 0.960665 + 0.154929i 9| 487.486082 | 1.608029e-06 | 0.952929 + 0.181478i 10| 569.131901 | 2.459271e-06 | 0.943462 + 0.210687i 11| 660.083684 | 3.758199e-06 | 0.931880 + 0.242737i 12| 761.402124 | 5.738207e-06 | 0.917721 + 0.277794i 13| 874.268807 | 8.752923e-06 | 0.900427 + 0.315986i 14| 1000.000000 | 1.333716e-05 | 0.879330 + 0.357389i 15| 1140.061995 | 2.029808e-05 | 0.853641 + 0.401992i 16| 1296.088211 | 3.085102e-05 | 0.822431 + 0.449661i 17| 1469.898248 | 4.682124e-05 | 0.784622 + 0.500088i 18| 1663.519097 | 7.094204e-05 | 0.738989 + 0.552724i 19| 1879.208790 | 1.072934e-04 | 0.684168 + 0.606690i 20| 2119.482727 | 1.619433e-04 | 0.618693 + 0.660680i 21| 2387.143012 | 2.438807e-04 | 0.541066 + 0.712827i 22| 2685.311132 | 3.663608e-04 | 0.449888 + 0.760566i 23| 3017.464361 | 5.488321e-04 | 0.344054 + 0.800486i 24| 3387.476311 | 8.196695e-04 | 0.223067 + 0.828203i 25| 3799.662107 | 1.220009e-03 | 0.087477 + 0.838291i 26| 4258.828711 | 1.809067e-03 | -0.060519 + 0.824359i 27| 4770.330980 | 2.671403e-03 | -0.216318 + 0.779363i 28| 5340.134118 | 3.926697e-03 | -0.372053 + 0.696340i 29| 5974.883239 | 5.742619e-03 | -0.515783 + 0.569724i 30| 6681.980865 | 8.351410e-03 | -0.631053 + 0.397471i Figure 1 shows the frequency response of the individual filters.