AKAmplitudeTracker - Amplitude in dB?

[Charlie Jay]

The docs do not seem to specify this, but is the detected amplitude of the AKAmplitudeTracker the amplitude in dB?

If not, is there a means by which I could track the amplitude of a signal from a microphone in dB (relatively accurately)?

[Aurelius Prochazka Ph.D.]

Mostly we deal with raw values 0-1 for amplitudes, not decibels which are more of a loudness indicator.  We sometimes use dB for gain.

Aure

[Charlie Jay]

Thanks for your response. I noticed the 0-1 range after playing around with it a bit.

What units does the amplitude tracker output (the raw value you mentioned)? 

[Aurelius Prochazka Ph.D.]

It doesn't really have a dimension.  It has to do with vibration of a speaker right, so I suppose you could call it a fraction of the maximum displacement.

Aure

[Charlie Jay]

That makes sense.

Excuse my lack of expertise, but do you have any advice for how I could convert the amplitude of you AKAmplitudeTracker into dB? 

In other words, to mimic the functionality of a decibel-o-meter? 

[Aurelius Prochazka Ph.D.]

Do the conversion, from AudioKit's source code

    /// Amplification Factor in db

    open dynamic var dB: Double {

        set {

            gain = pow(10.0, Double(newValue / 20))

        }

        get {

            return 20.0 * log10(gain)

        }

    }