Vowel recognition in noise for male, female and child voices. - Jeroen G. van Velden; Guido F. Smoorenburg (ICASSP, 1991)

Improved Speech Recognition Through Videotelephony: Experiments with the Hard of Hearing. - Han W. Frowein; Guido F. Smoorenburg; Liesbeth Pyters; Dolf Schinkel (IEEE J. Sel. Areas Commun., 1991)