Expression of emotions in singing is connected to a code with several parameters such as tempo, vibrato, rhythm, pitch, amplitude and timbre. The aim of this study is to understand how timbre expresses the performer’s emotions. Twelve professional singers were recorded while singing pieces of music with specific emotional content – Sadness, Joy, Anger and Fear – and a vocalise (Neutral). The data consisted of 432 vowels extracted from the perceptually accepted singing recordings judge by seven singing students. The results showed that formant frequencies changes are dependent on the emotions: Anger and Joy show higher formant frequency than Sadness and Fear. This investigation showed, also, that formants have specific functions: vowel discr...