Perfecting Vocal Technique: Distinguishing Vocal Registers Through Fourier Analysis

Abstract

Vocal registers are important for vocalists across different styles, ranging from contemporary to musical theater to classical singing. Although some researchers believe that clear register distinctions may not exist, it is quite common for singers to learn techniques that help achieve certain sounds when singing in these registers. Thus, we analyze four vocal registers—head/falsetto, mix, mix belt, and chest—using Fourier analysis of audio recordings of trained low-voice and high-voice singers. Low-voices are told to sing in falsetto, while high-voices are told to sing in head voice. Both sing a series of six notes, across vowels “Ah”, “Eh”, and “Ooh”. Through different methods of graphing, results indicated that vocal registers—especially chest and head/falsetto—can be distinguished, most likely due to differences in subglottal pressure. Additionally, graphing amplitudes of harmonics for higher notes above the passaggio, or the break from chest to head/falsetto, revealed a difference between mix and mix belt. We ultimately conclude that different registers within the modal register are distinct, which may be applicable to future works such as creating software that assist singers in improving their vocal technique.