Perceptual cues for place of articulation for the voiced pharyngeal and uvular consonants

A series of perceptual experiments was conducted to investigate the perceptual cues for place of articulation for the voiced pharyngeal /// and the voiced uvular /3/ consonants in Arabic. Synthetic consonant–vowel stimuli, in which the vowel was the long vowel /aa/ of Arabic, were used in the experiments. In the first experiment, stimulus continua were constructed by systematically varying the trajectories of the first and second formant frequencies (F1 and F2) independently between the values appropriate for the two consonants. In the second experiment, the bandwidth of F2 for the pharyngeal stimuli and the bandwidth of F1 for the uvular stimuli were manipulated. Results of the first experiment show that the onset value of F1(F1o) is essential in discriminating between the two consonants, while that of F2 is not. Results of the second experiment show that widening the bandwidth of F1 increases the percent of uvular responses and enhances the naturalness of the uvular stimuli, whereas it decreases substantially the number of pharyngeal responses. Increasing the bandwidth of F2 had no effect on either the percent identification of the pharyngeal or the naturalness of the synthetic stimuli.