The influence of creaky voice on formant frequency changes

Abstract

When disguising their voice, women may tend to lower their fundamental frequency so as to imitate a male’s voice. This implies a lowered fundamental frequency on the one hand and the production of creaky voice or creak over large sequences on the other. For speaker identification which additionally relies on formant frequency comparison, it is therefore of interest if the production of creaky voice implies an additional modification of the vocal tract and consequently has an effect on formant frequencies. In the present study, the second and third formant of 750 creaky and modal vowels of five female and four male speakers were compared. As a main result, a sex-specific difference has been observed. Creaky vowels produced by women show a lower second formant as compared to the same vowels produced by the same speaker using modal phonation. Changes in the third formant during low creaky voice disguise by women and, more generally, the effect on male formant values, was found to be inconsistent.