In a healthy voice, one in which the suspensory mechanism is doing its job of freeing and stabilising the larynx, a wide spectrum of colours is available. From ‘light’ to ‘dark’, this is an individual palette that responds instantly to the singer’s imagination and feelings. In a healthy voice, more or less subtle adjustments in laryngeal dynamics take place without resort to conscious technical manoeuvring.

The famed dramatic declamatory style of Gilbert-Louis Duprez apart, the deliberate lowering of the larynx, in order to darken the voice and add weight when singing, actually only gained prominence as a regular practice during the second quarter of 20th century. By this time, I imagine, all practical ties with the ideal bel canto balance had effectively been severed. In any case, the time it took to gain power and emotional depth naturally was probably thought unnecessary when a hefty ‘core’ of sound could be imposed so quickly, and seemingly safely, by fixing the larynx down. [Cornelius] Reid points to another perceived advantage or attraction of the ‘low larynx’. It ‘persuades the unwary that because something is being “done”, much is being accomplished’.

The ‘success’ of this so-called ‘covering’ technique or voix sombre, if strongly executed, is usually short-lived, depending on the strength of the singer’s throat to take the unnatural strain. Flexibility (both inside and outside the larynx) is severely reduced, a messa di voce with all its instrumental advantages is impossible, clarity of vowels is spoiled, high notes are forced, and the tone becomes unsteady. The voice is ‘inward-directed’, en dedans rather than open or outgoing. The singer’s message is thus held back, garbled or obscured.

Harrison, Peter T. Singing: Personal and performance values in training. Dunedin Academic Press Ltd. 2013.