Voice development under training with and without the influence of real-time visually presented biofeedback

This paper describes an investigation into the developmental nature of the voice under training with and without the influence of real-time visually presented biofeedback. Two subjects who had not previously experienced any form of vocal training took six singing lessons. One was taught conventionally, while the other was taught with the aid of a system known as Acoustic and Laryngeal Biofeedback Enhancement Real Time (ALBERT). Real-time biofeedback was presented based upon measures of (i) larynx closed quotient (CQ), (ii) spectral amplitude in the singer's formant frequency band relative to the spectral amplitude of the full band (ratio), and (iii) both parameters combined in a manner based on previously observed correlations between them. Results indicate generally increased sound pressure levels (SPL) of acoustic output and generally consistent increases in the level of CQ and ratio across consecutive lessons for both subjects.