[Characteristic] 4. Nasalisation. [Articulatory synthesis] Nasalisation is modelled directly by opening a velar connection to a parallel nasal tube that exchanges energy correctly with the pharyngeal-oral tube. No �kludges� are necessary. [Spectral reconstruction] 
Nasalisation approximated by various �kludges�, using additional poles and zeroes. A notch filter is usually used to �split� Formant 1�a characteristic of nasalisation.