In vocal pedagogy, the term "chest resonance" is frequently used to describe the buzzing sensation we feel in our rib cage when singing low notes. While this feeling is real, it is often misunderstood. To sing with a free and healthy range, we must distinguish between what we feel and how sound is actually amplified.
The bones of the chest and the rib cage do sympathetically vibrate on lower pitches. This is a result of bone conduction—the physical sensation of vibrating air molecules reflecting against our skeletal structure. However, it is important to realize that this sensation does not enhance our sound to any appreciable degree as we move away from our lowest pitches.
A common mistake for singers is attempting to maintain this lower vibrational feel as they ascend the scale. If you try to keep the chest vibrating while singing higher, you are effectively forcing the vocal cords to stay thick. This prevents them from thinning and stretching as required by the laws of nature, leading to strain, a "stuck" range, and potential vocal damage.
The chest cavity itself does not make a good acoustic resonator. Why? Because it houses the lungs, which are spongy and soft. In the world of acoustics, spongy surfaces absorb sound rather than reflecting and amplifying it.
The true powerhouse of resonance is the larynx itself! It is a firmer structure that provides a much more efficient environment for the "singer's ring" and tonal reinforcement.
While the buzz in your chest is a helpful indicator that you are in your lower register, it shouldn't be the goal of your technique as you move up. Let the chest vibrate where it will, but allow the resonance to shift upward as the vocal cords adjust. Trust your larynx to be the primary resonator and enjoy a voice that is free to climb.