Formant Analysis of Traditional Bulgarian Singing from Rhodope Region

Bulgarian traditional singing is very different from the singing found in Western countries. The technique of singing is similar to speech and the chest register is mainly used. Some authors claim that this characteristic timbre comes from tuning the first resonance of the vocal tract to the second harmonic of the sung note. In this paper traditional Bulgarian song "Yazhte i pijte, yoldashlar" from Rhodope region, sung a capella, was investigated in aspect of the vocal tract resonances tuning. The song was segmented and annotated manually and fragments containing sustained vowels were chosen. In total, 108 fragments with vowels /a/, /a/, /i/, and /o/ were analyzed. Then the formant frequencies of each sung vowel were examined. Two commonly used methods were compared in formant estimation task, namely linear prediction coding coefficients (LPC) and cepstrum. Formants were also estimated using PRAAT program. Finally, the LPC method was chosen for the song analysis.