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I'm using the AudioKit library with Swift for developing a simple iOS application that should be able to listen to frequencies of the range 3.000Hz - maybe 6000Hz.

So I'd like to just track the input frequency of the microphone within this range and to achieve this I tried to apply a filter effect on the input microphone to avoid picking up the frequency of several unwanted noises.

var mic: AKMicrophone
var silence: AKBooster
var filter: AKHighPassFilter
var tracker: AKFrequencyTracker

public init() {
   mic = AKMicrophone()
   filter = AKHighPassFilter(mic)
   filter.cutoffFrequency = 3000 // just get frequencyies above 3000Hz (highpass)
   filter.resonance = 0
   tracker = AKFrequencyTracker(filter)
   silence = AKBooster(tracker, gain: 0)
}

func start() {
    AKSettings.audioInputEnabled = true
    AudioKit.output = silence
    AudioKit.start()
}

func print() {
    print(tracker.frequency)
}

To sum that up: I know that the filter is changing something - but I can not really apply a frequency-filter for the range 3.000Hz + because I'm also getting values below 3.000Hz (like 2.0000 / 500 / etc) for the filtered frequency.

The AudiKit website has included some examples how to use the filters - But I can find no examples how to apply filters on the input-microphone to get a filtered frequency? http://audiokit.io/playgrounds/Filters/

Am I doing something the wrong way?
Is this really the functionality of the AudioKit-filters or didn't I get the right sense of filters?
Is there another way to filter for frequency-ranges?

0 Answers0