TFMethods.py 文件源码

def MOEar(self, correctionType = 'ELC'):
        """ Method to approximate middle-outer ear transfer function for linearly scaled
            frequency representations, using an FIR approximation of order 600 taps.
            As appears in :
            - A. Härmä, and K. Palomäki, ''HUTear – a free Matlab toolbox for modeling of human hearing'',
            in Proceedings of the Matlab DSP Conference, pp 96-99, Espoo, Finland 1999.
        Arguments          :
            correctionType : (string)     String which specifies the type of correction :
                                          'ELC' - Equal Loudness Curves at 60 dB (default)
                                          'MAP' - Minimum Audible Pressure at ear canal
                                          'MAF' - Minimum Audible Field
        Returns            :
            LTq            : (ndarray)    1D Array containing the transfer function, without the DC sub-band.
        """
        # Parameters
        firOrd = self.nfft
        Cr, fr, Crdb = self.OutMidCorrection(correctionType, firOrd, self.fs)
        Cr[self.nfft - 1] = 0.

        # FIR Design
        A = firwin2(firOrd, fr, Cr, nyq = self.fs/2)
        B = 1
        _, LTq = freqz(A, B, firOrd, self.fs)

        LTq = 20. * np.log10(np.abs(LTq))
        LTq -= max(LTq)
        return LTq[:self.nfft/2 + 1]