A perceptual study of whisper uttered by patients with bilateral recurrent nerve palsy (BRNP) revealed that, frequently, five vowels were perceived as syllables /hV/ and voiced fricative consonants were perceived as voiceless ones. Sound spectrographic analysis of the uttered samples showed that vowels uttered by BRNP had noise at the initial portion of the utterances like in a breathy voice onset and that voiced consonants uttered by BRNP had no formant transitions. On the other hand, the airflow rate in BRNP was very high during phonation and it was difficult for the patients to control the airflow. It was suggested that this difficulty of airflow control caused the decrease of the articulatory adjustments in BRNP.
