Analysis, synthesis and perception of the French nasal vowels

The purpose of the research reported here was to find out some acoustical and perceptual characteristics of the French nasal vowels. Acoustic analysis was made using a Pole-Zero Analysis-by-Synthesis procedure : below 4 kHz (in the case of male adult informants) the main acoustic correlates of the nasal vowels are the formant shifts and the introduction of two pole-zero pairs, one below F1, the other between F2 and F3. By means of a pole-zero synthesizer, synthetic stimuli were generated : two of them have the spectral characteristics of the real vowels [
\varepsilon
] and [
\tilde{\varepsilon}
], while the others are stimuli whose spectral characteristics are between those of [
\varepsilon
] and [
\tilde{\varepsilon}
]. Phonemic and phonetic perceptual tests were conducted. Their results show that formant shifts and pole-zero separation contribute almost equally to the decision on the phonemic identity of /
\varepsilon
/ versus /
\tilde{\varepsilon}
/, whereas pole-zero separation has a stronger effect than formant shifts in the phonetic judgment on nasality.