When we speak of the diaphragm that is so essential to our breathing, we properly call it the thoracic diaphragm, for there is another diaphragm located at the base of our pelvis called the perineal diaphragm. There are two diaphragms. Like the thoracic diaphragm, the perineal diaphragm is composed of a central tendon. We can locate the central tendon of the perineal diaphragm more accurately in the female than in the male, where it anchors the pelvis between anus and vagina.
Both males and females are prone to interfere with their breathing by holding on too tightly at the perineal diaphragm, at and around the central tendon. It is an area that we want to protect and we can wind up doing far too much. Free the pelvic floor. Let it fully receive the support of the chair on which you’re sitting. When you stand, let the perineal diaphragm belong to the ground while your head belongs to the sky. Release the central tendon; let it relax. You may feel quite vulnerable, maybe taller. That’s okay. Let every breath, especially the breath prior to speaking or singing, begin with a descent of the pelvic floor.
Imagine an empty glass cylinder with a membrane over both ends. Tug at the bottom membrane and distend it downward and the top membrane will correspond with a like motion. Let the thought of this action inhabit your breathing. Imagine a correspondence between the thoracic diaphragm and perineal diaphragm. It can become quite real.
When you sing, when you speak, let your sound be emitted from the floor of the pelvis. Let the perineal diaphragm descend in synch with the thoracic diaphragm. Relish the correspondence. It’s going to change the resonance quality of your voice for the better.