Amplitude domain quotient for characterization of the glottal volume velocity waveform estimated by inverse filtering

An amplitude-domain quotient for parametrization of the glottal source computed by inverse filtering is presented. The new quotient, AQ, is determined as the ratio between the amplitude of the AC-flow of the glottal waveform and the amplitude of the minimum of the flow derivative. This quotient can be used even though absolute flow values are not given by the recording equipment. The behaviour of AQ was compared to conventional time-based quotients by analysing voices produced by different phonation types. It was shown that phonation types can be quantified effectively when parametrization of the glottal flow estimated by inverse filtering is based on AQ.