Interactive digital inverse filtering and its relation to linear prediction methods

This paper is concerned with inverse filtering of the speech waveform in order to study the details of vocal tract excitation. An interactive digital inverse filtering system is described in which the advantages of previously described analogue and digital methods are combined to provide a facility with much greater convenience and power than either. Experience with this system is compared with that obtained using closed-period covariance-method linear prediction analysis. Evidence is presented to support the contention that since there is continued activity in the closed-glottis period there are definite advantages in having an interactive capability.