Constant interval distance between R1 and R2 of Spanish vowels sung at high pitch by sopranos

Abstract

Recently, Joliveau et al. [Nature 427, 116 (2004)] have studied the frequency distance between R1 resonance frequency and f0 of sopranos singing in English. Whereas at low-pitch singing this resonance frequency was roughly constant, at high-pitch singing R1 followed f0. This tendency held for vowels without lip rounding but not for those with lip rounding. Using CSRE45, at National School of Music of UNAM in Mexico City, R1 and R2 of the five tonic vowels (/a/, /e/, /i/, /o/, /u/) of Spanish words extracted from a traditional Mexican children’s song spoken or sung by 11 native-speaking sopranos with an average of 5 years of classical operatic training were analyzed. While speaking or singing at low or mid pitch, either resonance frequency fell within the distribution characteristic of each vowel, forming clusters. However, when singing at high pitch, there was a constant interval difference, irrespective of singer, between R1 and R2 of every vowel. Since it has a simple vowel system, and the frequency separations between formants of different vowels are relatively large, sopranos singing at high pitch in Spanish appear to easily maintain the interval difference between R1 and R2, and thereby the clarity of the vowels.